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A0800_A0800M-01(2006)奥氏体合金钢铸件中铁素体含量的估算

A0800_A0800M-01(2006)奥氏体合金钢铸件中铁素体含量的估算
A0800_A0800M-01(2006)奥氏体合金钢铸件中铁素体含量的估算

Designation:A800/A800M–01(Reapproved2006)

Standard Practice for

Steel Casting,Austenitic Alloy,Estimating Ferrite Content Thereof1

This standard is issued under the?xed designation A800/A800M;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.

A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.

1.Scope

1.1This practice covers procedures and de?nitions for estimating ferrite content in certain grades of austenitic iron-chromium-nickel alloy castings that have compositions bal-anced to create the formation of ferrite as a second phase in amounts controlled to be within speci?ed limits.Methods are described for estimating ferrite content by chemical,magnetic, and metallographic means.

1.2The grades covered by this practice are:CF-3,CF-3A, CF-8,CF-8A,CF-3M,CF-3MA,CF-8M,CF-8C,CG-8M,and CH-10.

1.3The values stated in either inch-pound units or SI units are to be regarded separately as standard.Within the text,the SI units are shown in brackets.The values stated in each system are not exact equivalents;therefore,each system must be used independently of the https://www.doczj.com/doc/eb14233599.html,bining values from the two systems may result in nonconformance with the practice.

1.4This standard does not purport to address the safety concerns,if any,associated with its use.It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2.Referenced Documents

2.1ASTM Standards:2

A351/A351M Speci?cation for Castings,Austenitic,for Pressure-Containing Parts

A370Test Methods and De?nitions for Mechanical Testing of Steel Products

A799/A799M Practice for Steel Castings,Stainless,In-strument Calibration,for Estimating Ferrite Content

A941Terminology Relating to Steel,Stainless Steel,Re-lated Alloys,and Ferroalloys

E38Methods for Chemical Analysis of Nickel-Chromium and Nickel-Chromium-Iron Alloys

E353Test Methods for Chemical Analysis of Stainless, Heat-Resisting,Maraging,and Other Similar Chromium-Nickel-Iron Alloys

E562Test Method for Determining V olume Fraction by Systematic Manual Point Count

2.2Constitution Diagrams:

Schoefer Diagram for Estimating Ferrite Content of Stain-less Steel Castings(1980revision)3

Schaeffler Diagram for Estimating Ferrite Content of Stain-less Steel Weld Metal4

DeLong Diagram for Estimating Ferrite Content of Stainless Steel Weld Metal5

2.3American Welding Society Speci?cation:

AWS A4.2,Procedures for Calibrating Magnetic Instru-ments to Measure the Delta Ferrite Content of Austenitic Stainless Steel Weld Metal6

3.Terminology

3.1De?nitions:

3.1.1ferrite—the ferromagnetic,body-centered,cubic-microstructural constituent of variable chemical composition in iron-chromium-nickel alloys.This may be formed upon solidi-?cation from the molten metal(delta ferrite)or by transforma-tion from austenite or sigma phase on cooling in the solid state (alpha ferrite).

3.1.2ferrite content—the proportion of total volume of an iron-chromium-nickel alloy present as the ferrite phase.

3.1.3ferrite number—the ferrite content expressed as an arbitrary number based on the magnetic response of the alloy in a weld deposit.

3.1.4ferrite percentage—the ferrite content expressed as a volume percent.

1This practice is under the jurisdiction of ASTM Committee A01on Steel, Stainless Steel,and Related Alloys and is the direct responsibility of Subcommittee

A01.18on Castings.

Current edition approved March1,2006.Published April2006.Originally approved https://www.doczj.com/doc/eb14233599.html,st previous edition approved in2001as A800/A800M–01.

2For referenced ASTM standards,visit the ASTM website,https://www.doczj.com/doc/eb14233599.html,,or contact ASTM Customer Service at service@https://www.doczj.com/doc/eb14233599.html,.For Annual Book of ASTM Standards volume information,refer to the standard’s Document Summary page on the ASTM website.

3Appendix of this practice.

4Metal Progress Data Book,American Society for Metals,Mid June1977,p. 161.

5Welding Journal,American Welding Society,V ol38,No.7,July1973,p. 293–s.

6Available from American Welding Society(AWS),550NW LeJeune Rd., Miami,FL33126.

Copyright?ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.

3.1.5heat treatment—the de?nitions in Terminology A941 are applicable to this practice.

4.Signi?cance and Use

4.1The tensile and impact properties,the weldability,and the corrosion resistance of iron-chromium-nickel alloy castings may be in?uenced bene?cially or detrimentally by the ratio of the amount of ferrite to the amount of austenite in the microstructure.The ferrite content may be limited by purchase order requirements or by the design construction codes gov-erning the equipment in which the castings will be used.The quantity of ferrite in the structure is fundamentally a function of the chemical composition of the alloy and its thermal history.Because of segregation,the chemical composition, and,therefore,the ferrite content,may differ from point to point on a casting.Determination of the ferrite content by any of the procedures described in the following practice is subject to varying degrees of imprecision which must be recognized in setting realistic limits on the range of ferrite content speci?ed. Sources of error include the following:

4.1.1In Determinations from Chemical Composition—Deviations from the actual quantity of each element present in an alloy because of chemical analysis variance,although possibly minor in each case,can result in substantial difference in the ratio of total ferrite-promoting to total austenite-promoting elements.Therefore,the precision of the ferrite content estimated from chemical composition depends on the accuracy of the chemical analysis procedure.

4.1.2In Determinations from Magnetic Response—Phases other than ferrite and austenite may be formed at certain temperatures and persist at room temperature.These may so alter the magnetic response of the alloy that the indicated ferrite content is quite different from that of the same chemical composition that has undergone different thermal treatment. Also,because the magnets or probes of the various measuring instruments are small,different degrees of surface roughness or surface curvature will vary the magnetic linkage with the material being measured.

4.1.3In Determinations from Metallographic Examination—Metallographic point count estimates of ferrite percentage may vary with the etching technique used for identi?cation of the ferrite phase and with the number of grid points chosen for the examination,as explained in Test Method E562.

4.2The estimation of ferrite percent by chemical composi-tion offers the most useful and most common method of ferrite control during melting of the metal.

4.3For most accurate estimate of ferrite percent,a quanti-tative metallographic method should be used.

5.Ordering Information

5.1Orders for material to this practice should include the following as required:

5.1.1Applicable ASTM product speci?cation or other docu-ment covering product requirements,

5.1.2Alloy grade,

5.1.3Required ferrite content range,in volume percent,of the castings after?nal heat treatment.Also,if desired by the purchaser,required ferrite content range,in ferrite number,for weld deposits(Note1)as deposited,and

5.1.4Supplementary requirements,if any,desired.

N OTE1—There may be a substantial decrease in the ferrite content of weld deposits after solution heat treatment in comparison with the as-deposited value.

6.General Caution

6.1In specifying ferrite content as required in5.1.3,the purchaser should not set limits that con?ict with applicable material speci?cation requirements:for example,a maximum limit of10%ferrite for Grade CF-3A in Speci?cation A351/ A351M for which the minimum tensile strength requirement is 77ksi[530MPa].

6.2When Supplementary Requirement S1is speci?ed,the purchaser should set ferrite content limits that are compatible with the measuring instrument to be used.

7.Estimation of Ferrite Content

7.1Estimation in the base metal of the casting by chemical composition in accordance with the Schoefer diagram(see Appendix X1):

7.1.1A chemical analysis of the heat from which the castings are poured shall include the following elements whether or not required by the chemical requirements of the product speci?cation:carbon,manganese,silicon,chromium, nickel,molybdenum,columbium,and nitrogen.

7.1.1.1Upon written agreement between the purchaser and the producer,an estimated nitrogen content may be reported instead of an amount determined by analysis of the speci?c heat if actual chemical analyses have been made for nitrogen in a sufficient number of heats of the same alloy type,produced by the same melting practice,to establish the average nitrogen content to be expected.

7.1.2The ferrite content of the casting shall be estimated from the central line of the diagram at the composition ratio of “chromium equivalent”(Cr e)to“nickel equivalent”(Ni e) determined from the following formula:

~Cr~%!11.5Si~%!11.4Mo~%!1Cb~%!24.99!/~Ni~%!

130C~%!10.5Mn~%!126~N20.02%!12.77!

5~Cr e!/~Ni e!

7.1.3When a product analysis is made by the purchaser,it shall include the elements listed in7.1.1.If a comparison is made of ferrite content estimated from a product analysis performed by the purchaser,with that estimated from the heat analysis(see7.1.1),the reproducibility data in the precision statements of Test Methods E353shall be used as a guide.

7.1.3.1Methods E38or Test Methods E353,as applicable, shall be used as referee chemical analysis methods.

7.2Estimation in weld deposits by chemical composition in accordance with the Schaeffler or DeLong diagrams:

7.2.1The ferrite content shall be estimated(a)from the deposit chemical analysis included on the electrode manufac-turer’s certi?ed material test report,or(b)from chemical analysis of a weld deposit pad made by the casting manufac-

turer.

7.3Estimation of ferrite content in heat,product,or weld metal may be made by the magnetic response or metallo-graphic methods by imposition of Supplementary Require-ments S1or S2,respectively.

8.Acceptance Standards

8.1Conformance with the required ferrite content range speci?ed in5.1.3as indicated by the estimation procedure of 7.1and7.2shall be the basis for acceptance of material supplied under this practice unless other methods of estimation are ordered as supplementary requirements,in which case the supplementary requirement shall be the basis of acceptance.

8.2If lack of conformance with the ferrite content range speci?ed in5.1.3is indicated by a product analysis made by the purchaser(7.1.3)and by a referee analysis as provided in 7.1.3.1,rejection of material shall be subject to the tests of7.3 as established by written agreement between the manufacturer and the purchaser.9.Certi?cation

9.1The manufacturer’s certi?cation shall be furnished to the purchaser stating that the material was sampled and tested in accordance with the speci?cation(including year date)and was found to meet the requirements.

9.2The test report shall contain the results of the actual chemical analyses required by7.1.1and7.2.1and the indicated ferrite content range.The estimates of ferrite content from magnetic measurements(S1)or from point counts(S2),or both,if ordered by the purchaser,also shall be reported.

9.3The test report shall be signed by an authorized agent of the manufacturer.

9.4The test report shall be furnished within?ve working days of shipment of the castings.

10.Keywords

10.1austenite;austenitic stainless steel;ferrite;Schoefer Diagram;steel castings

SUPPLEMENTARY REQUIREMENTS

The following supplementary requirements are for use when desired by the purchaser.They shall not apply unless speci?ed in the order,in which event the speci?ed methods of ferrite content estimation shall be employed by the manufacturer before shipment of the castings.

S1.Estimation of Ferrite Content by Measurement of Magnetic Response

S1.1The ferrite content of the heat from which the castings are poured shall be estimated from measurements made by primary or secondary instruments calibrated in accordance with the requirements of Practice A799/A799M.All measure-ments shall be made on material after the solution heat treatment required by the applicable product speci?cation,or, if any subsequent solution heat treatment is employed,then after the?nal solution heat treatment.

S1.1.1Location of measurements—base metal:

S1.1.1.1Measurements shall be made on the unstrained ends of tension test specimens from the same heat as the castings represented.Measurements may be made either before or after performance of the tension test.If a tension test is not required by the applicable product speci?cation,measurements may be made on a specimen cut from a keel block of a design in Fig.3of Test Methods and De?nitions A370.

S1.1.1.2When further speci?ed,measurements shall be made on the base metal of the castings,or a speci?ed sample of castings(not on weld repairs or other weld deposits),in locations designated on the design drawing or as otherwise agreed in writing between the purchaser and the manufacturer. S1.2The ferrite content of weld deposits shall be estimated from measurements made by primary or secondary instruments calibrated in accordance with the requirements of Speci?cation AWS A4.2.All measurements shall be made on weld deposits as deposited.

S1.2.1Location of measurements—weld deposits:

S1.2.1.1Measurements shall be made on a weld pad depos-ited in accordance with the electrode speci?cation.

S1.2.1.2When further speci?ed,measurements shall be made on repair or fabrication welds on castings in locations as agreed in writing between the purchaser and manufacturer.

S1.3Number of Measurements—Six measurements shall be made at random in each designated location.For instruments having probes making two contacts with the surface being measured,a“measurement”shall consist of a pair of readings taken with the probe oriented on perpendicular axes.

S1.4Surface Condition:

S1.4.1The instrument magnet or probe and the surface to be measured shall be dry and cleaned prior to testing to remove any scale,grease,lint,or dirt that could affect the accuracy of measurement.

S1.4.2Measurements shall be made more than0.25in.

[6.350mm]from the edge of a surface.When measurements are made on a curved surface the radius of curvature must be greater than0.375in.[9.525mm].

S1.5Acceptance Criteria:

S1.5.1The average of the ferrite contents estimated from measurements in each designated location shall be within the limits stated in the order,and not more than two individual measurements shall indicate ferrite contents less than or in excess of these limits.

S1.5.1.1If ferrite contents are estimated with an instrument that indicates for each measurement a value between an upper and a lower limit,more than one-half of all measurements shall be within the limits stated in the order.

S1.5.2Should the requirements of S1.5.1not be met,a referee estimation of ferrite content may be made by the metallographic method of Supplementary Requirement S2that shall take precedence over the magnetic

method.

S2.Estimation of Ferrite Content by Metallographic Examination

S2.1The locations of specimens to be examined shall be speci?ed on the drawing radiographic shooting sketch,or otherwise in writing by the purchaser.

S2.2Specimens shall be prepared so that metallographic examination may be made on three orthogonal planes.

S2.3The volume fraction of ferrite shall be estimated from the specimens by the point count practice recommended in Test Method E562.

APPENDIX

(Nonmandatory Information)

X1.NOTES TO SCHOEFER DIAGRAM

X1.1Fig.X1.1is applicable to alloys containing elements in the following ranges:

Weight,% Carbon0.20max

Manganese 2.00max

Silicon 2.00max

Chromium17.0to28.0

Nickel 4.0to13.0

Molybdenum 4.00max

Columbium 1.00max

Nitrogen0.20max

X1.2The Cr e/Ni e Composition Ratio necessary to produce alloy castings within a speci?ed ferrite content range may be read from the diagram at the intersection of the central line with the desired ferrite percentage,or may be obtained from Table X1.1.Example:For a ferrite content of12%the composition ratio should be1.234.

X1.3The estimated average ferrite content of castings may be read from the diagram at the intersection of the central line with the composition ratio calculated from the chemical composition of the heat from which they were poured.Because of errors in chemical analyses,the calculated ratio may

differ FIG.X1.1Schoefer Diagram for Estimating the Average Ferrite Content in Austenitic Iron-Chromium-Nickel Alloy

Castings

from the actual composition ratio and,as a result,the ferrite content may be higher or lower than indicated by the central line.Accordingly,if additional estimates of ferrite content are made by magnetic or metallographic methods,they can be expected to differ from the diagram value.The possible extent of this difference is shown by the broken lines.Example:If the composition ratio is 1.234,the indicated ferrite content is 12%with a probable maximum range from 8to 17%.Similar information is available in Table X1.2.

X1.4The ferrite content ranges are related to the upper and lower bounds of the composition ratio that are determined from the ratios 1.04Cr e /0.96Ni e and 0.96Cr e /1.04Ni e .These corre-

spond approximately to 61s deviations in all the ferrite promoting elements and 61s deviations in all the austenite promoting elements (based on standard deviations of indi-vidual elements as derived in a round-robin test project of the Steel Founders’Society of America).

X1.5Values of composition ratio (CR )for a given ferrite content (F ),or vice versa,may be determined mathematically from the equation of the central line:

CR 50.913.3888331022F 25.5817531024F 214.2286131026F 3

TABLE X1.2Volume Percent Ferrite Indicated by Composition Ratio

Composition

Ratio A 0.000.010.020.030.040.050.060.070.080.09U

0.00.00.00.00.50.5 1.0 1.5 1.5 2.00.800.00.00.00.00.00.00.00.00.00.0L 0.00.00.00.00.00.00.00.00.00.0U

2.5 2.5

3.0 3.5 3.5

4.0 4.5

5.0 5.0 5.50.900.00.50.5 1.0 1.0 1.5 2.0 2.0 2.5 3.0L 0.00.00.00.00.00.00.00.00.00.5U

6.0 6.5

7.07.07.5

8.08.5

9.09.59.51.00 3.0 3.5 4.0 4.0 4.5 5.0 5.0 5.5 6.0 6.0L 0.5 1.0 1.5 1.5 2.0 2.0 2.5 2.5 3.0 3.0U

10.010.511.011.512.012.513.013.514.014.51.10 6.57.07.57.58.08.59.09.59.510.0L 3.5 4.0 4.0 4.5 5.0 5.0 5.5 6.0 6.0 6.5U

15.015.516.517.017.518.018.519.520.020.51.2010.511.011.512.012.512.513.013.514.014.5L 7.07.07.58.08.58.59.09.510.010.0U

21.022.022.523.524.025.025.526.527.528.01.3015.015.516.016.517.018.018.519.019.520.0L 10.511.016.511.512.012.513.013.514.014.5U

29.030.031.032.033.034.035.036.037.038.01.4020.521.522.022.523.524.024.525.526.027.0L 15.015.015.516.016.517.017.518.018.519.0U

39.040.541.542.543.545.046.047.048.549.51.5027.528.529.530.031.032.033.033.534.535.5L 20.020.521.021.522.022.523.524.024.525.0U

50.551.552.554.055.056.056.557.558.559.51.6036.537.538.539.540.542.043.044.045.046.0L 26.026.527.528.029.029.530.531.032.033.0U

60.561.062.063.063.564.565.066.066.067.01.7047.048.049.050.051.552.053.054.055.056.0L

33.5

34.5

35.5

36.5

37.0

38.0

39.0

40.0

41.0

42.0

TABLE X1.1Composition Ratio Required for a Desired Ferrite Content

Volume Percent Ferrite

012345678900.9000.9330.9660.997 1.027 1.056 1.084 1.111 1.138 1.16310 1.187 1.211 1.234 1.256 1.277 1.297 1.317 1.336 1.354 1.37120 1.388 1.405 1.420 1.436 1.450 1.464 1.478 1.491 1.504 1.51630 1.528 1.540 1.551 1.562 1.573 1.584 1.594 1.604 1.614 1.62340 1.633 1.643 1.652 1.661 1.671 1.680 1.689 1.699 1.708 1.71850 1.728 1.737 1.747 1.758 1.768 1.779 1.790 1.801 1.813 1.82560 1.837 1.850

1.863

1.877

1.891

1.906

1.921

1.937

1.953

1.970

70

1.988

TABLE X1.2Continued

0.000.010.020.030.040.050.060.070.080.09 Composition

Ratio A

U68.068.569.069.570.5>70

1.8057.058.058.559.560.061.06

2.062.56

3.06

4.0

L43.044.045.046.047.048.049.050.051.051.5

U>70

1.9064.565.566.066.567.068.068.569.069.570.0

L52.553.554.555.056.057.057.558.559.060.0

U>70

2.00>70

L61.061.562.063.063.564.064.565.566.066.5

U>70

2.10>70

L67.067.568.069.069.570.0>70

A For a given composition ratio the ferrite content estimate will be found at the intersection of the appropriate line and column.The?gures immediately above and below on the lines U and L indicate the probable upper and lower bounds of the ferrite range that may be expected.

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A1016铁素体合金钢,奥氏体合金钢和不锈钢钢管的通用要求规范

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铸件质量检查标准

一、目的: 为了确保外协标准铸件、成品铸件质量符合工艺、技术要求,为了满足产品特性,结合相关文件特制定本标准。 二、适用范围: 本办法适用于我公司产品外协、采购、装配过程中、全部铸件质量检查标准。 三、检查标准: 3.1、铸件结构要符合设计要求或加工工艺要求。无特殊要求时按铸件通用标准执行。通用标准等级分为: 交货验收技术条件标准;铸件质量分等通则(合格品、一等品、优等品)材质、检验方法;工艺和材料规格等一般性规则。 3.2、铸件成品检验。铸件成品检验包括:相关技术条件的检验、表面质量检验、几何尺寸检验等项内容。 ①相关技术条件的检验。包括铸件化学成分、机械性能等检验内容。机械性能检验和金相及化学成分检验等技术条件的检验,均必须按相关国家标准执行检验(此处略)。 ②表面质量检验。机械加工生产一线人员在工艺过程中对铸造毛坯的检查主要是对其外观铸造缺陷(如有无沙眼、沙孔、疏松、有无浇不足、铸造裂纹等)的检验;以及毛坯加工余量是否满足加工要求的检验。 表3-1铸件外观质量检验项目(GB6060.1—1985)

表3-2 铸件表面粗糙度(R a 值μm)(GB6414—1986) ③铸件成品几何尺寸检验。主要一种是采用划线法检查毛坯的加工余量是否足够。另一种方法是:用毛坯的参考基准面(也称工艺基准面)作为毛坯的检验基准面的相对测量法(需要测量相对基准面的尺寸及进行简单换算)。 表3-3 铸件尺寸公差数值(mm)(GB6414—1986) 注:铸件基本尺寸≤10mm 时,其公差等级提高3 级;大于10mm 至等于15mm 时,其公差等级提高2级;大于16mm 至25mm 时,其公差等级提高1 级。

铁素体耐热钢

为确保火力发电的长期稳定和减少CO2排放问题,开发超临界压力火力发电用高强度耐蚀耐热钢是不可或缺的,使用这种钢能够使蒸汽高温高压化,从而提高发电效率,减少CO2排放。 人们通常将蒸汽温度超过566℃、压力超过24.1MPa的设备称为USC设备。目前,USC设备的最高蒸汽温度已达到610℃,日本等国家正在进行蒸汽温度达到650℃的高强度铁素体耐热钢的研究开发。作为630℃级汽轮机用铁素体耐热钢,日本开发了MTR10A(10Cr-0.7Mo-1.8W-3Co-VNb)、HR1200(11Cr-2.6W-3Co-NiVNb)和TOS110(10Cr-0.7Mo-1.8W-3Co-VNb)。 对于650℃级铁素体耐热钢,日本从材料结构方面研究了微细组织在晶界附近长时间稳定的问题。9Cr-3W-3Co-0.2V-0.05Nb-0.08C钢添加了在晶界容易产生偏析的硼后,根据该钢在650℃时的蠕变断裂数据,为抑制试验用钢生成氮化硼(Boronnitride简称BN),因此不添加氮。无添加硼的钢在1千小时左右的长时间运转后,蠕变断裂强度急剧下降,但随着硼含量的增加,在长时间运转后能抑制蠕变断裂强度的劣化。由于该钢没有添加氮,因此Z相的生成不会导致长时间运转后蠕变断裂强度的劣化。长时间运转后蠕变断裂强度的劣化是由于在蠕变过程中M23C6碳化物凝聚粗化会导致马氏体组织迅速恢复所致。硼在晶界附近的M23C6碳化物中浓缩,可以长时间抑制晶界附近的M23C6碳化物在蠕变过程中发生凝聚粗化,使晶界附近的微细板条状-块状组织保持长时间不变。 根据在650℃、80MPa时的蠕变速度-时间曲线可知,添加硼后发生大的变化的是加速蠕变的开始时间延长了。由此可使最小蠕变速度变得更低,断裂寿命延长。添加硼,可以抑制晶界附近发生局部蠕变变形,使变形在晶界附近和晶粒内变得更加均匀,还可提高蠕变延性,从而提高蠕变疲劳寿命。在添加140ppm硼的9Cr钢中,当氮为80ppm左右时,蠕变强度变得极大。 作为650℃级高效USC设备用钢,日本在耐热钢的研究方面领先于欧美。为解决能源供给和减少CO2排放这两个课题,因此对耐热钢的高强度化、高温化、尤其是确保长时间运转可靠性的要求非常高,研究开发新一代耐热钢对火力发电来说今后将起越来越重要的作用

合金钢中各元素对其性能的影响

合金钢中各元素对其性能的影响 1、碳(C):钢中含碳量增加,屈服点和抗拉强度升高,但塑性和冲击性降低,当碳量0.23%超过时,钢的焊接性能变坏,因此用于焊接的低合金结构钢,含碳量一般不超过0.20%。碳量高还会降低钢的耐大气腐蚀能力,在露天料场的高碳钢就易锈蚀;此外,碳能增加钢的冷脆性和时效敏感性。 2、硅(Si):在炼钢过程中加硅作为还原剂和脱氧剂,所以镇静钢含有0.15-0.30%的硅。如果钢中含硅量超过0.50-0.60%,硅就算合金元素。硅能显著提高钢的弹性极限,屈服点和抗拉强度,故广泛用于作弹簧钢。在调质结构钢中加入 1.0-1.2%的硅,强度可提高15-20%。硅和钼、钨、铬等结合,有提高抗腐蚀性和抗氧化的作用,可制造耐热钢。含硅1-4%的低碳钢,具有极高的导磁率,用于电器工业做矽钢片。硅量增加,会降低钢的焊接性能。 3、锰(Mn):在炼钢过程中,锰是良好的脱氧剂和脱硫剂,一般钢中含锰0.30-0.50%。在碳素钢中加入0.70%以上时就算“锰钢”,较一般钢量的钢不但有足够的韧性,且有较高的强度和硬度,提高钢的淬性,改善钢的热加工性能,如16Mn钢比A3屈服点高40%。含锰11-14%的钢有极高的耐磨性,用于挖土机铲斗,球磨机衬板等。锰量增高,减弱钢的抗腐蚀能力,降低焊接性能。 4、磷(P):在一般情况下,磷是钢中有害元素,增加钢的冷脆性,使焊接性能变坏,降低塑性,使冷弯性能变坏。因此通常要求钢中含磷量小于0.045%,优质钢要求更低些。

5、硫(S):硫在通常情况下也是有害元素。使钢产生热脆性,降低钢的延展性和韧性,在锻造和轧制时造成裂纹。硫对焊接性能也不利,降低耐腐蚀性。所以通常要求硫含量小于0.055%,优质钢要求小于0.040%。在钢中加入0.08-0.20%的硫,可以改善切削加工性,通常称易切削钢。 6、铬(Cr):在结构钢和工具钢中,铬能显著提高强度、硬度和耐磨性,但同时降低塑性和韧性。铬又能提高钢的抗氧化性和耐腐蚀性,因而是不锈钢,耐热钢的重要合金元素。 7、镍(Ni):镍能提高钢的强度,而又保持良好的塑性和韧性。镍对酸碱有较高的耐腐蚀能力,在高温下有防锈和耐热能力。但由于镍是较稀缺的资源,故应尽量采用其他合金元素代用镍铬钢。 8、钼(Mo):钼能使钢的晶粒细化,提高淬透性和热强性能,在高温时保持足够的强度和抗蠕变能力(长期在高温下受到应力,发生变形,称蠕变)。结构钢中加入钼,能提高机械性能。还可以抑制合金钢由于火而引起的脆性。在工具钢中可提高红性。 9、钛(Ti):钛是钢中强脱氧剂。它能使钢的内部组织致密,细化晶粒力;降低时效敏感性和冷脆性。改善焊接性能。在铬18镍9奥氏体不锈钢中加入适当的钛,可避免晶间腐蚀。 10、钒(V):钒是钢的优良脱氧剂。钢中加0.5%的钒可细化组织晶粒,提高强度和韧性。钒与碳形成的碳化物,在高温高压下可提高抗氢腐蚀能力。 11、钨(W):钨熔点高,比重大,是贵生的合金元素。钨与碳形

高温用无缝铁素体合金钢公称管

高温用无缝铁素体合金钢公称管 SA-335/SA-335M 一、本标准适用于高温用公称和最小壁厚的铁素体无缝合金钢管。 二、尺寸、外形 1.外径和壁厚允许偏差见下表(冷拔) 钢管外径正偏差(+)负偏差(-) ≤48.30.40 0.40 >48.3----≤114.3 0.79 0.79 >114.3---≤219.1 1.59 0.79 >219.1---≤457.2 2.38 0.79 壁厚-12.5% 注:壁厚正偏差标准没有规定,但有重量限制。任何一根钢管的重量应不大于规定值的10%,而不小于3.5% 2.长度 定尺长度的允许偏差:+6/-0mm。 3.弯曲度

成品钢管应相当直。 4.端头外形 除非另有规定,公称管以平的端部供货。管端部的所有毛刺须全部清除。 管端平滑无毛刺。 三、技术要求 1.钢的熔炼成分应符合下表的规定 级别 化学成分% C Mn P ≤ S ≤ Si Cr Mo V ≥ P11 0.05-0.15 0.30-0.60 0.025 0.025 0.50-1.00 1.00-1.50 0.44-0. 65 P12 0.05-0.15 0.30-0.61 0.025 0.025 ≤ 0.50 0.80-1.25 0.44-0. 65 P22 0.05-0.15 0.30-0.60 0.025 0.025 ≤ 0.50 1.90-2.60 0.87-1. 13 P23 0.04-0.10-0.00.0≤ 1.90-0.05-0.0.20-0.3

0.10 0.60 30 10 0.50 2.60 30 0 P91 0.08- 0.12 0.30- 0.60 0.0 20 0.0 10 0.20- 0.50 8.0-9. 5 0.85-1. 05 0.18-0.2 5 P92 0.07- 0.13 0.30- 0.60 0.0 20 0.0 10 ≤ 0.50 8.50- 9.50 0.30-0. 60 0.15-0.2 5 注:P23中其他元素的含量:W:1.45~1.75,Nb:0.02~0.08,B:0.0005~0.006,N≤0.03,AL≤0.03 P91中其他元素的含量:Nb:0.06~0.10,N:0.03~0.07,Ni≤0.40,AL≤0.04 P92中其他元素的含量:W:1.5~2.0,Nb:0.04~0.09,B:0.001~0.006,N:0.03~0.07,Ni≤0.40,AL≤0.04 2.热处理制度;详见标准第5.3条。

铸件检验规范

铸件检验规范 SANY标准化小组 #QS8QHH-HHGX8Q8-GNHHJ8-HHMHGN#

采购物品检验规范(铸件) 目的:为了加强本公司对铸件质量控制,保证本公司的产品质量,特制订潍坊中云机器有限公司铸件进厂检验办法。 适用范围:进入本公司的所有铸件。 内容:铸件的检验主要包括铸件表面质量的检验和铸件内在质量以及铸件质量的综合评定。本公司主要进行铸件表面质量的检验,其他均不做检验。 铸件表面质量的检验: 1、铸件表面不得有明显孔眼(气孔、缩孔、渣眼、砂眼、铁豆),裂纹(热裂、冷裂、温裂),表面缺陷(粘砂、结疤、夹砂、冷隔),形状缺陷(多肉、浇不足、变形、料口毛刺)等影响产品的外观和强度缺陷。 2、进厂的铸件表面必须清砂干净,铸件缺陷修补部位应打磨平整,无凹凸、裂纹等缺陷。 3、铸造的毛坯材质符合图纸资料要求,检测铸铁、铸钢铸铝等毛坯件具体的化学成分不作分析。 4、定期对零件的硬度进行抽检,抽检率10%。 5、模具毛坯的几何形状和尺寸符合图纸资料要求,要求加工处要留有足够的加工量,错型公差符合要求(检测以单边最小数为准),具体尺寸见下表(单位:mm): 工量,可以通过加工去除表面痕迹。 10、铸件螺纹孔内螺丝旋入四个螺距之内不允许有缺陷,四个螺距之外缺陷直径不大于1.5mm,且整个螺纹孔内不多于2个。 11铸件的尺寸检验公差值按照下表执行,一般取其最低的一级执行:

求,在检验铸件尺寸时应遵循以下规定: 铸件的尺寸和几何形状应符合零件图与铸件图要求。 外购铸件首次必须将模样或首件送检,并认真填写检验记录。 铸件进厂应按10%进行抽检,若铸件尺寸不合格时,应逐件进行检验,不合格的铸件予以报废。

常用合金钢

常用合金钢(知识扩展)一.合金钢分类与编号二.低合金结构钢Q345、Q420 三. 机器零件用钢40Cr、65Mn、60Mn2Si、20Cr、20CrMnTi、GCr15 四.合金工具钢9SiCr、CrWMn、W18Cr4V、Cr124Cr5MoSiV 五.特殊性能钢1Cr13、9Cr18、1Cr17、1Cr18Ni9Ti、ZGMn13 合金钢分类 1.按合金元素含量多少分类:按合金元素含量多少分类:按合金元素含量多少分类低合金钢(合金总量低于5 %)中合金钢(合金总量为5 %~10 %)高合金钢(合金总量高于10 %)2.按用途分类:按用途分类:按用途分类合金结构钢低合金结构钢(也称普通低合金钢) 合金渗碳钢、合金调质钢、合金弹簧钢滚珠轴承钢合金工具钢合金刃具钢(含低合金刃具钢、高速钢) 合金模具钢(含冷模具钢、热模具钢) 量具用钢特殊性能钢不锈钢、耐热钢、耐磨钢合金钢编号首部用数字标明碳质量分数: 结构钢以万分之一为单位的数字(两位数), 工具钢和特殊性能钢以千分之一为单位的数字(一位数)来表示碳质量分数,而工具钢的碳质量分数超过1%时,碳质量分数不标出。在表明碳质量分数数字之后,用元素的化学符号表明钢中主要合金元素,质量分数由其后面的数字标明:平均质量分数少于 1.5%时不标数, 平均质量分数为 1.5%~2.49%、 2.5%~3.49%……时,相应地标以2、3……。专用钢用其用途的汉语拼音字首来标明. 如GCr15表示碳质量分数约1.0%、铬质量分数约 1.5%(特例)的滚珠轴承钢. Y40Mn,表示碳质量分数为0.4%、锰质量分数少于 1.5%的易切削钢. 普通低合金钢Q345 用途主要用于制造桥梁,船舶,车辆,锅炉,压力容器,输油输气管道,大型钢结构等.在热轧空冷状态下使用,组织为细晶粒的F+P,不再热处理. 化学成分wt% C Mn Si V Nb Ti 0.015 0.18 ~ 1.0 ~0.55 0.02 0.20 1.6 ~0.15 ~0.06 厚度mm <16 16~35 35~50 σs MPa ≥345 ≥325 ≥295 σb MPa 470~630 0.02 ~0.2 机械性能δ5 % Akv(20℃) J 34 21~22 GB/T1591-1994 Q345包括旧钢号12MnV ,14MnNb ,16Mn ,18Nb ,16MnCu Q420 普通低合金钢在正火状态下使用,组织为F+S 化学成分wt% V Nb Ti 0.02 ~0.2 0.015 ~0.06 0.02 ~0.2 δ5 % C ≤0.20 厚度mm <16 Mn Si Cr ≤0.40 Ni ≤0.70 1.0 ~0.55 1.7 34 18~19 16~35 GB/T1591-1994 ≥380 35~50 Q345包括旧钢号15MnVN ,14MnVTiRE 机械性能σs MPa σb MPa ≥420 520~680 ≥400 Akv(20℃) J 合金调质钢(低淬透性) 40Cr 热处理毛坯尺寸<25mm 用途:用于制造汽车、拖拉机、机床和其它机器上的各种重要零件,如机床齿轮、主轴、汽车发动机曲轴、连杆、螺栓、进气阀主要化学成分wt% C Mn Si Cr Mo 机械性能(≥)退火态H B 淬火℃回火℃σb σs δ5 ψ Akv % % J MP MP a a 0.37 0.5 0.17 0.8 0.07 850 520 980 785 9 45 47 2 0 油水~~~~~0.44 0.8 0.37 1.1 0.12 7 油(GB/T3077-1999)合金弹簧钢钢号C 65Mn 60Mn2Si 主要成分w % Mn Si Cr 热处理淬火℃回火℃机械性能σs MPa σb MPa δ10 ψ % % 65Mn 0.62 ~0.70 60Si2 0.56 Mn ~0.64 0.90 ~1.20 0.60 ~0.90 0.17 ~0.37 1.50 ~2.00 ≤ 830 540 0.25 油800 1000 8 30 ≤ 870 480 1200 1300 5 0.35 油GB/T1222-1985 25 65Mn 60Mn2Si钢应用举例:截面≤25mm的弹簧,例如车箱缓冲卷簧合金渗碳钢(低淬透性合金渗碳钢低淬透性) 20Cr 低淬透性用途:可制造汽车、拖拉机中的变速齿轮,内燃机上的凸轮轴、活塞销等机器零件.能同时承受强烈的摩擦磨损,较大的交变载荷,特别是冲击载荷机械性能(≥)主要化学成分wt% 热处理℃C Mn Si Cr 渗预淬回σb σs δ ψ Akv 5 碳备火火MP M J % % a P 处 a 理0.17 0.5 0.20 0.7 9 ~~~~3 0.24 0.8 0.40 1.0 0 8 8 0 水油780 2 0 ~820 0 水, 油8 3 5 5 4 0 毛坯尺寸m m 10 4 47 <0 1 5 GB/T3077-1999 合金渗碳钢(中淬透性合金渗碳钢中淬透性) 中淬透性20CrMnTi 主要化学成分wt% C Mn Si Cr Ti 毛渗预淬回σb σs δ ψ Ak 坯尺v 碳备火火MP MP % % 2 0 寸处℃m a a 理J m 9 3 0 8 8 0 油7 2 7 0 0 0 油1 85 1 4 55 < 0 0 0 5 15 8 GB/T3077-1999 0 热处理℃机械性能(≥)0.17 0.80 0.1 1.0 7~~~~0.23 1.10 0.3 1.3 7 0.04 ~0.10 滚珠轴承钢GCr15 用途:制造滚动轴承的滚动体(滚珠、滚柱、滚针),内外套圈等. 或制造精密量具、冷冲模、机床丝杠等耐磨件. 淬回

碳素钢和低合金钢的定义

碳钢 主要指力学性能取决于钢中的碳含量,而一般不添加大量的合金元素的钢,有时也称为普碳钢或碳素钢。 碳钢也叫碳素钢,指含炭量WC小于2%的铁碳合金。 碳钢除含碳外一般还含有少量的硅、锰、硫、磷。 按用途可以把碳钢分为碳素结构钢、碳素工具钢和易切削结构钢三类,碳素结构钢又分为建筑结构钢和机器制造结构钢两种; 按冶炼方法可分为平炉钢、转炉钢和电炉钢; 按脱氧方法可分为沸腾钢(F)、镇静钢(Z)、半镇静钢(b)和特殊镇静钢(T Z); 按含碳量可以把碳钢分为低碳钢(WC ≤ 0.25%),中碳钢(WC0.25%—0.6%)和高碳钢(WC>0.6%); 按磷、硫含量可以把碳素钢分为普通碳素钢(含磷、硫较高)、优质碳素钢(含磷、硫较低)和高级优质钢(含磷、硫更低)和特级优质钢。 一般碳钢中含碳量较高则硬度越大,强度也越高,但塑性较低。 按国际标准,把钢区分为非合金钢和合金钢两大类,非合金钢是通常叫做碳素钢的一大钢类,钢中除了铁和碳以外,还含有炉料带入的少量合金元素Mn、Si、Al,杂质元素P、S及气体N、H、O等。合金钢则是为了获得某种物理、化学或力学特性而有意添加了一定量的合金元素Cr、Ni、Mo、V,并对杂质和有害元素加以控制的另一类钢。 原则上讲,合金钢分为低合金钢、中合金钢和高合金钢,顾名思义,以含有合金元素的总量来加以区分,总量低于3%称为低合金钢,5~10%为中合金钢,大于10%为高合金钢。在国内习惯上又将特殊质量的碳素钢和合金钢称为特殊钢,全国31家特钢企业专门生产这类钢,如优质碳素结构钢、合金结构钢、碳素工具钢、合金工具钢、高速工具钢、碳素弹簧钢、合金弹簧钢、轴承钢、不锈钢、耐热钢、电工钢,还包括高温合金、耐蚀合金和精密合金等等。在钢的分类上,近年虽努力向国际通用标准靠拢,但还有许多不同之处。 ①随着特钢向“特”、“精”、“高”发展,向深加工方向延伸,特钢的领域越来越窄。美国特钢协会将特钢定位在工模具钢、不锈钢、电工钢、高温合金和镍合金。日本把结构钢和高强度钢归并在特钢范畴。随着我国普钢企业的技术改造和工艺进步,特钢企业的产品领域也在缩小,1999年普钢厂已生产特钢产品总量的34%。 ②国外的低合金钢,实际上是我们所熟悉的低合金高强度钢,属于特殊钢范畴,在美国叫做高强度低合金钢(HSLA—Steel),俄罗斯及东欧各国称为低合金建筑钢,日本命名为高张力钢。而在国内,首先是把低合金钢划入了普钢范围,概念上的区别导致在产品质量上的差异。在名称上也几经变化,如低合金建筑钢、普通低合金钢、低合金结构钢,至1994年叫做低合金高强度结构钢(GB/T1591—94)。到目前为止,从发表的资料文献来看,低合金钢的名称仍然随着国家、企业和作者而异。

耐热钢的分类与用途资料

一、不锈钢: 按成分可分为Cr系(400系列)、Cr-Ni系(300系列)、Cr-Mn-Ni(200系列)及析出硬化系(600系列)。200 系列—铬-镍-锰奥氏体不锈钢300 系列—铬-镍奥氏体不锈钢301—延展性好,用于成型产品。也可通过机械加工使其迅速硬化。焊接性好。抗磨性和疲劳强度优于304不锈钢。302—耐腐蚀性同304,由于含碳相对要高因而强度更好。303—通过添加少量的硫、磷使其较304更易切削加工。304—即18/8不锈钢。GB牌号为0Cr18Ni9。309—较之304有更好的耐温性。316—继304之后,第二个得到最广泛应用的钢种,主要用于食品工业、制药行业和外科手术器材,添加钼元素使其获得一种抗腐蚀的特殊结构。由于较之304其具有更好的抗氯化物腐蚀能力因而也作“船用钢”来使用。SS316则通常用于核燃料回收装置。18/10级不锈钢通常也符合这个应用级别。[1] 不锈钢水桶 型号321—除了因为添加了钛元素降低了材料焊缝锈蚀的风险之外其他性能类似304。400 系列—铁素体和马氏体不锈钢。408—耐热性好,弱抗腐蚀性,11%的Cr,8%的Ni。409—最廉价的型号(英美),通常用作汽车排气管,属铁素体不锈钢(铬钢)。410—马氏体(高强度铬钢),耐磨性好,抗腐蚀性较差。416—添加了硫改善了材料的加工性能。420—“刃具级”马氏体钢,类似布氏高铬钢这种最早的不锈钢。也用于外科手术刀具,可以做的非常光亮。430—铁素体不锈钢,装饰用,例如用于汽车饰品。良好的成型性,但耐温性和抗腐蚀性要差。440—高强度刃具钢,含碳稍高,经过适当的热处理后可以获得较高屈服强度,硬度可以达到58HRC,属于最硬的不锈钢之列。最常见的应用例子就是“剃须刀片”。常用型号有三种:440A、440B、440C,另外还有440F(易加工型)。500 系列—耐热铬合金钢。600 系列—马氏体沉淀硬化不锈钢。不锈钢 630—最常用的沉淀硬化不锈钢型号,通常也叫17-4;17%Cr,4%Ni。 “不锈钢”一词不仅仅是单纯指一种不锈钢,而是表示一百多种工业不锈钢,所开发的每种不锈钢都在其特定的应用领域具有良好的性能。成功的关键首先是要弄清用途,然后再确定正确的钢种。有关不锈钢的进一步详细情况可参见由NiDI 编制的"不锈钢指南"软盘。幸而和建筑构造应用领域有关的钢种通常只有六种。它们都含有17~22%的铬,较好的钢种还含有镍。添加钼可进一步改善大气腐蚀性,特别是耐含氯化物大气的腐蚀。 二耐热钢: 耐热钢是指在高温下工作的钢材。耐热钢的发展与电站、锅炉、燃气轮机、内燃机、航空发动机等各工业部门的技术进步密切相关。由于各类机器、装置使用的温度和所承受的应力不同,以及所处环境各异,因此所采用的钢材种类也各不相同。这里所谈的温度是个相对的概念。最早在锅炉和加热炉中使用的材料是低碳钢,使用的温度一般在200℃左右,压力仅为0.8MPa。知道现在使用的锅炉用低碳钢,如20g,使用温度也不超过450℃,工作压力不超过6MPa。随着各类动力装置的使用温度不断提高,工作压力迅速增加,现代耐热钢的使用温度已高达700℃,使用的环境也变得更加复杂与苛刻。现在,耐热钢的使用温度范围为200~800℃,工作压力为几兆帕到几十兆帕,工作环境从单纯的氧化气氛,发展到硫化气氛、混合气氛以及熔盐和液金属等更复杂的环境。

铸 件 检 验 规 范。

采购物品检验规范(铸件) 目的:为了加强本公司对铸件质量控制,保证本公司的产品质量,特制订潍坊中云机器有限公司铸件进厂检验办法。 适用范围:进入本公司的所有铸件。 内容:铸件的检验主要包括铸件表面质量的检验和铸件内在质量以及铸件质量的综合评定。本公司主要进行铸件表面质量的检验,其他均不做检验。 铸件表面质量的检验: 1、铸件表面不得有明显孔眼(气孔、缩孔、渣眼、砂眼、铁豆),裂纹(热裂、冷裂、温裂),表面缺陷(粘砂、结疤、夹砂、冷隔),形状缺陷(多肉、浇不足、变形、料口毛刺)等影响产品的外观和强度缺陷。 2、进厂的铸件表面必须清砂干净,铸件缺陷修补部位应打磨平整,无凹凸、裂纹等缺陷。 3、铸造的毛坯材质符合图纸资料要求,检测铸铁、铸钢铸铝等毛坯件具体的化学成分不作分析。 4、定期对零件的硬度进行抽检,抽检率10%。 5、模具毛坯的几何形状和尺寸符合图纸资料要求,要求加工处要留有足够的加工量,错型公差符合要求(检测以单边最小数为准),具体尺寸见下表(单位:mm): 6、铸件表面不能有裂纹,毛坯的浇口、顶杆痕迹允许留有痕迹,但必须留有加工量,可以通过加工去除表面痕迹。 9、铸件加工后的表面不允许有铸态表皮存在。 10、铸件螺纹孔内螺丝旋入四个螺距之内不允许有缺陷,四个螺距之外缺陷直径不大于1.5mm,且整个螺纹孔内不多于2个。 11铸件的尺寸检验公差值按照下表执行,一般取其最低的一级执行: 铸件尺寸公差值(GB6414—1999)

12、为避免成批铸件因尺寸不合格报废、保证铸件满足机械加工和使用性能要求,在检验铸件尺寸时应遵循以下规定: 12.1铸件的尺寸和几何形状应符合零件图与铸件图要求。 12.2外购铸件首次必须将模样或首件送检,并认真填写检验记录。 12.3铸件进厂应按10%进行抽检,若铸件尺寸不合格时,应逐件进行检验,不合格的铸件予以报废。

4130合金钢成分及性能

合金结构钢介绍 这类钢,由于具有合适的淬透性,经适宜的金属热处理后,显微组织为均匀的索氏体、贝氏体或极细的珠光体,因而具有较高的抗拉强度和屈强比(一般在0.85左右),较高的韧性和疲劳强度,和较低的韧性-脆性转变温度,可用于制造截面尺寸较大的机器零件。 4130结构钢 4130结构钢具有高的强度和韧性,淬透性较高,在油中临界淬透直径15~70mm;钢的热强度性也较好,在500℃以下具有足够的高温强度,但550℃时其强度显著下降;当合金元素在下限时焊接相当好,但接近上限时焊接性中等,并在焊前需预热到175℃以上;钢的可切削性良好,冷变形时塑性中等;热处理时在300~350℃的范围有第一类回火脆性;有形成白点的倾向。 4130结构钢性能及应用 合金结构钢4130 标准:ASTM A29/A29M-04 这种钢通常是在调质状态下使用,当含碳量为下限的钢也可用作要求心部强度较高的渗碳钢。在中型机械制造业中主要用于制造截面较大、在高应力条件下工作的调质零件,如轴、主轴以及受高负荷的操纵轮、螺栓、双头螺栓、齿轮等;在化工工业中用来制造焊接零件、板材与管材构成的焊接结构和在含有氮氢介质中工作的温度不超过250℃的高压导管;在汽轮机、锅炉制造业中用于制造 450℃以下工作的紧固件、500℃以下受高压的法兰和 4130结构钢化学成分 碳 C :0.28~0.33 硅 Si:0.15~0.35 锰 Mn:0.40~0.60 硫 S :允许残余含量≤0.040 磷 P :允许残余含量≤0.035 铬 Cr:0.80~1.10 镍 Ni:允许残余含量≤0.030 铜 Cu:允许残余含量≤0.030 钼 Mo:0.15~0.25[2]

铁素体型耐热钢发展主要分为四个发展阶段

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新型铁素体耐热钢CB2的焊接及热处理工艺研究吴富强 摘要:随着我国经济的快速发展,提高火电机组的热效率是一项重要和紧迫的 任务。而火电机组效率的提高主要在于提高蒸汽的压力和温度。这就对火电机组 的相关设备用钢特别是高温承压部件用钢的高温性能提出了更高的要求,目前我 国自主研发新型耐热钢ZG12Cr9Mo1Co1NiVNbNB(CB2)以良好性能逐渐应用于 火力发电厂热力系统设备的耐热钢材。因此,新型耐热钢CB2焊接及热处理工艺 的研究是目前火电建设施工技术领域亟待解决的问题。 关键词:新型耐热钢;CB2钢;热处理工艺; 1引言 CB2钢是欧洲COST536项目研发的新型铁素体耐热钢,可用于 600℃/620℃30MPa的第二代超超临界机组汽轮机高温部件及管道,目前已实现 国产化,但尚处于初步应用阶段。据查,国内焊接及热处理工艺方面的研究文献 极少,为突破国外厂商的技术壁垒,充分发挥其性能并推广应用,迫切需要掌握 该钢种现场焊接和热处理施工工艺。 2研究内容 2.1CB2钢焊接性分析 CB2钢材料是经过淬火+回火处理的供货状态,其组织为回火马氏体。CB2钢 是在P91钢基础上加入适量的Co,同时加入少量的Nb和B,适当增加Mo的含 量得到的。 ①焊接热裂纹敏感性 由于CB2钢合金程度高,其硼、硫含量低,锰含量高,这些因素共同决定了 其在施焊冷却过程中,随着温度的降低导致产生的低溶点共晶物少,又由于其自 身线膨胀系数小,因此,CB2钢的热裂纹敏感性不大。 ②焊接冷裂纹敏感性 由于CB2钢合金元素含量高,碳当量高,临界冷却速度低,奥氏体稳定性很大,冷却时不易发生正常的珠光体转变,从而冷却到较低温度时发生了马氏体转变。在焊接过程中,淬硬将会形成较多的的晶格缺陷(空位、位错),同时在热 力不均及应力作用下易形成裂纹源,且该裂纹源在后续工作条件下产生裂纹的所 需要吸收的能量低,故CB2钢产生冷裂纹倾向大。 ③化学成分Co对焊接接头的影响 CB2钢是在P91钢基础上加入适量的Co,可抑制铁素体的析出、降低硫含量,同时可发生固溶强化,提高钢的回火稳定性。其缺点是易发生过时效倾向而使钢 变脆。合适的焊后热处理工艺可以获得相对细小弥散分布的析出相,进一步提高CB2钢的力学性能。 2.2CB2钢焊接材料选择分析 ①CB2钢化学成分及性能分析 ZG12Cr9Mo1Co1NiVNbNB(CB2)钢是在P91钢基础上加入1.27%的Co,同时 加入少量的Nb和B,适当增加Mo的含量得到的,目的是为了提高钢材的高温力学性能。CB2钢化学成分: C0.13Cr9.11Ni0.14Co1.27Mo1.59V0.054Nb0.21B0.01N0.015 CB2钢室温下力学性能:抗拉强度≥690MPa,屈服强度≥490MPa,伸长率 ≥15%,断面收缩率≥35%,冲击功≥27J,布氏硬度210-260HB。 ②CB2钢焊材的选用

ASTM A335&A335M-20033 高温用无缝铁素体合金钢管

Designation:A 335/A 335M –03 Standard Speci?cation for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service 1 This standard is issued under the ?xed designation A 335/A 335M;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon (e )indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense. 1.Scope * 1.1This speci?cation 2covers nominal wall and minimum wall seamless ferritic alloy-steel pipe intended for high-temperature service.Pipe ordered to this speci?cation shall be suitable for bending,?anging (vanstoning),and similar form-ing operations,and for fusion welding.Selection will depend upon design,service conditions,mechanical properties,and high-temperature characteristics. 1.2Several grades of ferritic steels (see Note 1)are covered.Their compositions are given in Table 1. N OTE 1—Ferritic steels in this speci?cation are de?ned as low-and intermediate-alloy steels containing up to and including 10%chromium. 1.3Supplementary requirements (S1to S7)of an optional nature are provided.These supplementary requirements call for additional tests to be made,and when desired,shall be so stated in the order together with the number of such tests required.1.4The values stated in either inch-pound units or SI units are to be regarded separately as standard.Within the text,the SI units are shown in brackets.The values stated in each system are not exact equivalents;therefore,each system must be used independently of the https://www.doczj.com/doc/eb14233599.html,bining values from the two systems may result in nonconformance with the speci?-cation.The inch-pound units shall apply unless the “M”designation of this speci?cation is speci?ed in the order. N OTE 2—The dimensionless designator NPS (nominal pipe size)has been substituted in this standard for such traditional terms as “nominal diameter,”“size,”and “nominal size.” 2.Referenced Documents 2.1ASTM Standards: A 450/A 450M Speci?cation for General Requirements for Carbon,Ferritic Alloy,and Austenitic Alloy Steel Tubes 3A 999/A 999M Speci?cation for General Requirements for Alloy and Stainless Steel Pipe 3 E 213Practice for Ultrasonic Examination of Metal Pipe and Tubing 4 E 309Practice for Eddy-Current Examination of Steel Tu-bular Products Using Magnetic Saturation 4 E 381Method of Macroetch Testing Steel Bars,Billets,Blooms,and Forgings 5 E 527Practice for Numbering Metals and Alloys (UNS)3E 570Practice for Flux Leakage Examination of Ferromag-netic Steel Tubular Products 42.2Other Documents: SNT-TC-1A Recommended Practice for Nondestructive Personnel Quali?cation and Certi?cation 6 SAE J 1086Practice for Numbering Metals and Alloys (UNS)73.Ordering Information 3.1Orders for material under this speci?cation should include the following,as required,to describe the desired material adequately: 3.1.1Quantity (feet,metres,or number of lengths),3.1.2Name of material (seamless alloy steel pipe),3.1.3Grade (Table 1), 3.1.4Manufacture (hot-?nished or cold-drawn),3.1.5Size using one of the following:3.1.5.1NPS and schedule number, 3.1.5.2Outside diameter and nominal wall thickness,3.1.5.3Outside diameter and minimum wall thickness,3.1.5.4Inside diameter and nominal wall thickness,and 3.1.5.5Inside diameter and minimum wall thickness.3.1.6Length (speci?c or random), 1 This speci?cation is under the jurisdiction of ASTM Committee A01on Steel,Stainless Steel and Related Alloysand is the direct responsibility of Subcommittee A01.10on Stainless and Alloy Steel Tubular Products. Current edition approved Apr.10,2003.Published May 2003.Originally approved in https://www.doczj.com/doc/eb14233599.html,st previous edition approved in 2002as A 335/A 335M-02.2 For ASME Boiler and Pressure Vessel Code applications see related Speci?-cation SA-335in Section II of that Code. 3 Annual Book of ASTM Standards ,V ol 01.01.4Annual Book of ASTM Standards ,V ol 03.03.5 Annual Book of ASTM Standards ,V ol 03.01.6 Available from the American Society for Nondestructive Testing,1711Arlin-gate Plaza,PO Box 28518,Columbus,OH 43228-0518.7 Available from Society of Automotive Engineers,400Commonwealth Drive,Warrendale,PA 15096. 1 *A Summary of Changes section appears at the end of this standard. Copyright ?ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.

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