ASTM A450 is a standard specification for the general requirements of carbon and low alloy steel tubes.

ASTM A450是碳和低合金钢管一般要求的标准规范。

What is ASTM A450?  ASTM A450是什么？

A450/A450M Standard Specification for General Requirements for Carbon and Low Alloy Steel Tubes.

A450/A450M碳素钢和低合金钢管一般要求的标准规范。

The ASTM A450/A450M specification sets forth the general requirements that govern the production and testing of carbon and low alloy steel tubes. Its comprehensive scope covers aspects ranging from dimensions and tolerances to mechanical properties and tests, ensuring a cohesive and standardized approach to tube manufacturing.

ASTM A450/A450M规范规定了碳和低合金钢管生产和测试的一般要求。其综合范围涵盖了从尺寸和公差到机械性能和测试的各个方面，确保了管材制造的连贯性和标准化方法。

The specification covers the following requirements:

本规范包括以下要求：

• Steel samples must be melt processed and either ingot cast or strand cast.
• 钢样必须经过熔融处理，可以是铸锭或铸坯。
• Heat and product analyses must be performed on the steel materials.
• 必须对钢材进行热量和产品分析。
• The requirements are mandatory, with the exceptions of 5.3 and Sections 6, 7, 18, 19, 20, 21, 22, 23, and 24.
• 这些要求是强制性的，但5.3和第6、7、18、19、20、21、22、23和24节除外。

ASTM A450 was published by ASTM International on November 1, 2021.

ASTM A450由ASTM国际组织于2021年11月1日发布。

What is the other name of low carbon steel? 低碳钢的另一个名字是什么？

Also known as mild steel, low carbon steel has low strength relative to steel with higher carbon levels. 

低碳钢也称为低碳钢，相对于碳含量较高的钢，其强度较低。

What are the 4 types of carbon steel? 碳钢的四种类型是什么？

Carbon steel is broken down into four classes based on carbon content:

碳钢根据碳含量分为四类：

• Low-carbon steel. 0.05 to 0.15% carbon (plain carbon steel) content.
• 低碳钢。0.05至0.15%的碳（普通碳钢）含量。
• Medium-carbon steel. Approximately 0.3–0.5% carbon content. ...
• 中碳钢。碳含量约为0.3-0.5%。。。
• High-carbon steel. Approximately 0.6 to 1.0% carbon content. ...
• 高碳钢。碳含量约为0.6%至1.0%。。。  
• Ultra-high-carbon steel. Approximately 1.25–2.0% carbon content.
• 超高碳钢。碳含量约为1.25-2.0%。

Ensuring Dimensional Precision确保尺寸精度

1.Dimensions and Tolerances: ASTM A450/A450M leaves no room for ambiguity when it comes to tube dimensions and tolerances. By providing strict guidelines for outside diameter, wall thickness, and length, it fosters uniformity across various applications.

1.尺寸和公差：ASTM A450/A450M在管材尺寸和公差方面没有模糊之处。通过为外径、壁厚和长度提供严格的指导方针，它促进了各种应用的均匀性。

2. Straightness and Finish: The standard's meticulous stipulations regarding tube straightness and surface finish contribute to the overall aesthetic and functional qualities of the tubes, ensuring they meet the rigorous demands of industrial applications.

2 .平直度和光洁度：该标准对管材平直度和表面光洁度的细致规定有助于提高管材的整体美学和功能质量，确保其满足工业应用的严格要求。

Mechanical Properties and Tests机械性能和试验

1. Tensile and Hardness Tests: The ASTM A450/A450M specification mandates essential tests to evaluate the mechanical properties of the steel tubes. Tensile strength and hardness assessments provide insights into the tubes' ability to withstand external forces and pressures.

1.拉伸和硬度试验：ASTM A450/A450M规范要求进行基本试验，以评估钢管的机械性能。抗拉强度和硬度评估提供了对管子承受外力和压力能力的见解。

2.Flattening Test: By subjecting tubes to the flattening test, the standard ensures that tubes can endure the deformation caused by compression, a crucial consideration for applications involving pressure containment.

2.压扁试验：通过对管子进行压扁试验，该标准确保管子能够承受压缩引起的变形，这是涉及压力容器应用的关键考虑因素。

A Pillar of Quality Assurance质量保证的支柱

ASTM A450/A450M doesn't just address physical attributes; it embodies a philosophy of excellence. By delineating stringent requirements and test procedures, it safeguards the reliability and quality of carbon and low alloy steel tubes. This standard serves as a benchmark against which manufacturers and engineers can gauge their products, fostering confidence in their performance.

ASTM A450/A450M不仅涉及物理属性；它体现了卓越的哲学。通过制定严格的要求和测试程序，它保障了碳和低合金钢管的可靠性和质量。该标准可作为制造商和工程师衡量其产品的基准，增强对其性能的信心。

Applications and Beyond应用程序及其他

The influence of ASTM A450/A450M reverberates across a myriad of industries:

ASTM A450/A450M的影响波及无数行业：

1. Construction: Structural integrity is paramount in construction. The standard's specifications ensure that steel tubes used in buildings, bridges, and other structures meet the highest quality standards.

1.施工：结构完整性在施工中至关重要。该标准的规范确保建筑物、桥梁和其他结构中使用的钢管符合最高质量标准。

2.Mechanical Engineering: In mechanical systems, precision and dependability are non-negotiable. ASTM A450/A450M-compliant tubes form the backbone of machines, mechanisms, and conveyance systems.

2.机械工程：在机械系统中，精度和可靠性是不可谈判的。符合ASTM A450/A450M标准的管子构成了机器、机构和输送系统的支柱。

3.Energy and Utilities: From pipelines to heat exchangers, steel tubes play a pivotal role in energy production and distribution. The standard's provisions guarantee the safety and efficiency of these critical components.

3.能源和公用事业：从管道到换热器，钢管在能源生产和分配中起着关键作用。该标准的规定保证了这些关键部件的安全性和效率。

A Conclusive Standard结论性标准

In the intricate tapestry of industrial manufacturing, ASTM A450/A450M stands as a decisive thread, weaving together precision, reliability, and excellence. Its stipulations transcend the realm of specifications; they embody a commitment to quality that resonates across diverse applications. With ASTM A450/A450M, carbon and low alloy steel tubes find their compass, guiding them toward uncompromising standards of performance and integrity.

在工业制造的复杂挂毯中，ASTM A450/A450M是一条决定性的线，将精度、可靠性和卓越性编织在一起。其规定超越了规范的范畴；它们体现了对质量的承诺，在不同的应用程序中引起了共鸣。通过ASTM A450/A450M，碳和低合金钢管找到了自己的指南针，引导他们朝着不妥协的性能和完整性标准前进。

Scope范围

1. 1. This specification  covers a group of requirements which, with the exceptions of 6.3 and Sections 7, 8, 19, 20, 21,22, 23, 24, and 25, are mandatory requirements to the following ASTM tubular product specifications:
   2. 1.1本规范涵盖了一组要求，除6.3和第7、8、19、20、21、22、23、24和25节外，这些要求是以下ASTM管材规范的强制性要求：

A These designations refer to the latest issue of the respective specifications.

A这些名称是指最新版本的相应规范。
1.2 One or more of Sections 6.3, 7, 8, 19, 20, 21, 22, 22.1,24, and 25 apply when the product specification or purchase order has a requirement for the test or analysis described by these sections.

1.2当产品规范或采购订单对这些章节所述的测试或分析有要求时，第6.3、7、8、19、20、21、22、22.1、24和25节中的一个或多个适用。
1.3 In case of conflict between a requirement of the product specification and a requirement of this general requirement specification only the requirement of the product specification need be satisfied.

1.3如果产品规范的要求与本通用要求规范的要求之间存在冲突，则只需满足产品规范中的要求。
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. The inch-pound units shall apply unless the “M” designation (SI) of the product specification is specified in the order.

1.4以国际单位制或英寸-磅单位表示的值应单独视为标准值。在文本中，国际单位制显示在括号中。每个系统中所述的值可能不是完全等效的；因此，每个系统都应独立使用。将两个系统的值结合起来可能会导致不符合标准。除非订单中规定了产品规格的“M”名称（SI），否则应采用英寸-磅单位。

Ordering Information订购信息

4.1 It is the purchaser’s responsibility to specify in the purchase order all ordering information necessary to purchase the needed material. Examples of such information include, but are not limited to, the following:

4.1买方有责任在采购订单中指定购买所需材料所需的所有订购信息。此类信息的示例包括但不限于以下内容：
4.1.1 Quantity (feet, metres, or number of lengths),

4.1.1数量（英尺、米或长度），

4.1.2 Specificiation number with grade or class, or both, as applicable and year date,

4.1.2带等级或类别或两者的指定编号（如适用）和年份日期，
4.1.3 Manufacture (hot-finished or cold-finished),

4.1.3制造（热加工或冷加工），
4.1.4 Size (outside diameter and minimum wall thickness),

4.1.4尺寸（外径和最小壁厚），
4.1.5 Length (specific or random),

4.1.5长度（特定或随机），
4.1.6 Test report required (see Section 27),

4.1.6所需的测试报告（见第27节），

4.1.7 Choice of testing track from the options listed in Test Methods A1058 when material is ordered to an M suffix (SI units) product standard. If the choice of test track is not specified in the order, then the defaultASTM test track shall be used as noted in Test Methods A1058.

4.1.7当材料订购为M后缀（SI单位）产品标准时，从试验方法A1058中列出的选项中选择测试轨道。如果订单中未指定测试轨道的选择，则应按照测试方法A1058中的说明使用默认的ASTM测试轨道。
4.1.8 Supplementary Requirements, and

4.1.8补充要求，以及

4.1.9 Additional requirements.

4.1.9附加要求。

5. Process过程

5.1 The steel may be made by any process.

5.1钢可以通过任何工艺制成。
5.2 If a specific type of melting is required by the purchaser,it shall be as stated on the purchase order.

5.2如果买方要求特定类型的熔化，则应按照采购订单上的规定进行。

5.3 The primary melting may incorporate separate degassing or refining and may be followed by secondary melting,such as electroslag remelting or vacuum-arc remelting.

5.3一次熔化可包括单独的脱气或精炼，随后可进行二次熔化，如电渣重熔或真空电弧重熔。

5.4 Steel may be cast in ingots or may be strand cast. When steel of different grades is sequentially strand cast, identification of the resultant transition material is required. The producer shall remove the transition material by an established procedure that positively separates the grades.

5.4钢可以铸为钢锭，也可以铸为铸坯。当不同等级的钢按顺序铸坯时，需要对所得过渡材料进行标识。生产商应通过既定的程序去除过渡材料，以明确区分等级。

6. Chemical Composition化学成分

6.1 Samples for chemical analysis, and method of analysis shall be in accordance with Test Methods, Practices, and Terminology A751.

6.1化学分析样品和分析方法应符合试验方法、规程和术语A751。
6.2 Heat Analysis—If the heat analysis reported by the steel producer is not sufficiently complete for conformance with the heat analysis requirements of the applicable product specification to be fully assessed, the manufacturer may complete the assessment of conformance with such heat analysis requirements by using a product analysis for the specified elements that were not reported by the steel producer, provided that product analysis tolerances are not applied and the heat analysis is not altered.

6.2热分析——如果钢铁生产商报告的热分析不够完整，无法完全评估其是否符合适用产品规范的热分析要求，制造商可以通过对钢铁生产商未报告的指定元素进行产品分析来完成对此类热分析要求的合规性评估，前提是不应用产品分析公差，也不改变热分析。
6.3 Product Analysis—Product analysis requirements and options, if any, are contained in the product specification.

6.3产品分析——产品规范中包含产品分析要求和选项（如有）。

7. Tensile Properties拉伸性能

7.1 The material shall conform to the requirements as to tensile properties prescribed in the individual specification.

7.1材料应符合个别规范中规定的拉伸性能要求。
7.2 The yield strength corresponding to a permanent offset of 0.2 % of the gage length or to a total extension of 0.5 % of the gage length under load shall be determined.

7.2应确定对应于标距长度0.2%的永久偏移或负载下标距长度0.5%的总延伸的屈服强度。
7.3 If the percentage of elongation of any test specimen is less than that specified and any part of the fracture is more than 3 ⁄ 4 in. [19.0 mm] from the center of the gage length, as indicated by scribe marks on the specimen before testing, a retest shall be allowed.

7.3如果任何试样的伸长率小于规定值，并且断裂的任何部分距离标距中心超过3/4英寸[19.0毫米]，如试验前试样上的划线标记所示，则应允许重新试验。

8. Standard Weights标准重量

8.1 The calculated weight per unit length, based upon a specified minimum wall thickness, shall be determined by the following equation:

8.1根据规定的最小壁厚，每单位长度的计算重量应通过以下方程式确定：

W ＝C (D- t ) t       (1)

where:哪里
  C = 10.69 [0.0246615],
  W = weight, lb/ft [kg/m],
  D = specified outside diameter, in. [mm], and
  t = specified minimum wall thickness, in. [mm]
  8.2 The permissible variations from the calculated weight per foot [kilogram per metre] shall be as prescribed in Table 1.

8.2每英尺计算重量[千克每米]的允许偏差应符合表1的规定。

TABLE 1 Permissible Variations in Weight Per Unit Length  A 

A These permissible variations in weight apply to lots of 50 tubes or more in sizes 4 in. [101.6 mm] and under in outside diameter, and to lots of 20 tubes or more in sizes over 4 in. [101.6 mm] in outside diameter.

A这些允许的重量变化适用于外径为4英寸[101.6毫米]及以下的50根或更多管子的批次，以及外径超过4英寸[101.6mm]的20根或更多试管的批次。

9. Permissible Variations in Wall Thickness壁厚允许偏差

9.1 Variations from the specified minimum wall thickness shall not exceed the amounts prescribed in Table 2.

9.1与规定最小壁厚的偏差不得超过表2中规定的量。
9.2 For tubes 2 in. [50.8 mm] and over in outside diameter and 0.220 in. [5.6 mm] and over in thickness, the variation in wall thickness in any one cross section of any one tube shall not exceed the following percentage of the actual mean wall at the section. The actual mean wall is defined as the average of the thickest and thinnest wall in that section.

9.2对于外径为2英寸[50.8毫米]及以上、厚度为0.220英寸[5.6毫米]及以下的管子，任何一根管子的任何一个横截面的壁厚变化不得超过该截面实际平均壁厚的以下百分比。实际平均壁厚定义为该截面中最厚和最薄壁的平均值。

Seamless tubes ±10 % 无缝管±10%

Welded tubes ± 5 % 焊接管±5%

9.3 When cold-finished tubes as ordered require wall thick-
nesses 3 ⁄ 4 in. [19.1 mm] or over, or an inside diameter 60 % or less of the outside diameter, the permissible variations in wall thickness for hot-finished tubes shall apply.

9.3当订购的冷加工管需要壁厚时-

3⁄4 in.[19.1 mm]或以上，或内径为外径的60%或以下，热加工管壁厚的允许偏差应适用。

TABLE 2 Permissible Variations in Wall Thickness   

A These permissible variations in wall thickness apply only to tubes, except internal-upset tubes, as rolled or cold-finished, and before swaging, expanding,bending, polishing, or other fabricating operations.

A这些允许的壁厚变化仅适用于轧制或冷加工的管子，内部镦粗管除外，以及在型锻、膨胀、弯曲、抛光或其他制造操作之前。

Permissible Variations in Outside Diameter外径允许偏差

10.1 Except as provided in 10.2, variations from the specified outside diameter shall not exceed the amounts prescribed in Table 3.

10.1除10.2中规定外，与规定外径的偏差不得超过表3中规定的量。
10.2 Thin-wall tubes usually develop significant ovality (out of roundness) during final annealing, or straightening, or both.The diameter tolerances of Table 3 are not sufficient to provide for additional ovality expected in thin-wall tubes, and, for such tubes, are applicable only to the mean of the extreme (maximum and minimum) outside diameter readings in any one cross section. However, for thin wall tubes the difference in extreme outside diameter readings (ovality) in any one cross section shall not exceed the following ovality allowances:

10.2薄壁管在最终退火或矫直或两者同时进行时通常会出现明显的椭圆度（不圆度）。表3中的直径公差不足以提供薄壁管中预期的额外椭圆度，对于此类管，仅适用于任何一个横截面中极端（最大和最小）外径读数的平均值。然而，对于薄壁管，任何一个横截面的极端外径读数（椭圆度）的差异不得超过椭圆度公差

TABLE 3 Permissible Variations in Outside Diameter 

A Except as provided in 10.2, these permissible variations include out-of-roundness. These permissible variations in outside diameter apply to hot-finished seamless, welded and cold-finished seamless tubes before other fabricating operations such as upsetting, swaging, expanding, bending, or polishing.

A除10.2中规定外，这些允许的偏差包括不圆度。外径的这些允许变化适用于热加工无缝管、焊接无缝管和冷加工无缝管，然后再进行其他制造操作，如镦粗、型锻、膨胀、弯曲或抛光。

Permissible Variations in Length允许的长度变化

11.1 Variations from the specified length shall not exceed the amounts prescribed in Table 4.

11.1规定长度的变化不得超过表4中规定的金额。

TABLE 4 Permissible Variations in Length A 

A These permissible variations in length apply to tubes before bending. They apply to cut lengths up to and including 24 ft [7.3 m]. For lengths greater than 24 ft [7.3m], the above over-tolerances shall be increased by 1 ⁄ 8 in. [3 mm] for each 10 ft [3m] or fraction thereof over 24 ft or 1 ⁄ 2 in. [13 mm], whichever is the lesser.

A这些允许的长度变化适用于弯曲前的管子。它们适用于长度不超过24英尺[7.3米]的切割。对于长度大于24英尺[7.3米]的情况，上述超差应每10英尺[3米]或超过24英尺或1/2英寸[13毫米]的部分增加1⁄8英寸[3毫米]，以较小者为准。

12. Permissible Variations in Height of Flash on Electric-Resistance-Welded Tubes

12.电阻焊管闪光高度的允许偏差

12.1 For tubes over 2 in. [50.8 mm] in outside diameter, or over 0.135 in. [3.44 mm] in wall thickness, the flash on the inside of the tubes shall be mechanically removed by cutting to a maximum height of 0.010 in. [0.25 mm] at any point on the tube.

12.1对于外径超过2英寸[50.8毫米]或壁厚超过0.135英寸[3.44毫米]的管子，应通过在管子上的任何点切割到最大高度0.010英寸[0.25毫米]来机械去除管子内侧的飞边。
12.2 For tubes 2 in. [50.8 mm] and under in outside diameter and 0.135 in. [3.4 mm] and under in wall thickness,the flash on the inside of the tube shall be mechanically removed by cutting to a maximum height of 0.006 in. [0.15mm] at any point on the tube.

12.2对于外径为2英寸[50.8毫米]及以下、壁厚为0.135英寸[3.4毫米]及以内的管子，应通过在管子上的任何点切割至最大高度0.006英寸[0.15毫米]来机械去除管子内侧的飞边。

Straightness and Finish直线度和表面处理

13.1 Finished tubes shall be reasonably straight and have smooth ends free of burrs. They shall have a workmanlike finish. Surface imperfections (see Note 1) may be removed by grinding, provided that a smooth curved surface is maintained,and the wall thickness is not decreased to less than that permitted by this or the product specification. The outside diameter at the point of grinding may be reduced by the amount so removed.

13.1成品管应合理笔直，端部光滑无毛刺。它们应具有精湛的表面处理。表面缺陷（见注释1）可以通过研磨去除，前提是保持光滑的曲面，壁厚不小于本规范或产品规范允许的厚度。磨削点处的外径可以减少所去除的量。
N OTE 1—An imperfection is any discontinuity or irregularity found in the tube.

注1--缺陷是指管子中发现的任何不连续或不规则之处。

14. Repair by Welding焊接修补

14.1 Repair welding of base metal defects in tubing is permissible only with the approval of the purchaser and with the further understanding that the tube shall be marked “WR” and the composition of the deposited filler metal shall be suitable for the composition being welded. Defects shall be thoroughly chipped or ground out before welding and each repaired length shall be reheat treated or stress relieved as required by the applicable specification. Each length of repaired tube shall be tested hydrostatically as required by the product specification.

14.1只有在买方批准的情况下，才允许对管子中的母材缺陷进行补焊，并进一步理解管子应标记为“WR”，沉积的填充金属的成分应适合焊接的成分。焊接前应彻底凿除或磨掉缺陷，每个修复的长度应按照适用规范的要求进行再热处理或消除应力。每段修复的管子应按照产品规范的要求进行静水压试验。
14.2 Repair welding shall be performed using procedures and welders or welding operators that have been qualified in accordance with ASME Boiler and Pressure Vessel Code,Section IX.

14.2应使用符合ASME锅炉和压力容器规范第九节规定的合格程序和焊工或焊接操作员进行补焊。

15. Retests复试

15.1 If the results of the mechanical tests of any group or lot do not conform to the requirements specified in the individual specification, retests may be made on additional tubes of double the original number from the same group or lot, each of which shall conform to the requirements specified.

15.1如果任何组或批次的机械试验结果不符合个别规范中规定的要求，则可以对同一组或批次中原始数量两倍的额外管子进行重新试验，每根管子都应符合规定的要求。

16. Retreatment在处理

16.1 If the individual tubes or the tubes selected to represent any group or lot fail to conform to the test requirements, the individual tubes or the group or lot represented may be retreated and resubmitted for test. Not more than two reheat treatments shall be permitted.

16.1如果单个试管或选择代表任何组或批次的试管不符合测试要求，则可以退回单个试管或代表的组或批次并重新提交测试。不允许进行两次以上的再热处理。

17. Test Specimens试样

17.1 Test specimens shall be taken from the ends of finished tubes prior to upsetting, swaging, expanding, or other forming operations, or being cut to length. They shall be smooth on the ends and free of burrs and flaws.

17.1试样应在镦粗、型锻、膨胀或其他成型操作或切割成一定长度之前从成品管的端部取出。端部应光滑，无毛刺和缺陷。
17.2 If any test specimen shows flaws or defective machining, it may be discarded and another specimen substituted.

17.2如果任何试样出现缺陷或加工缺陷，则可以丢弃并更换另一个试样。

18. Method of Mechanical Testing机械测试方法

18.1 The specimens and mechanical tests required shall be made in accordance with Annex A2 of Test Methods and Definitions A370 if inch-pound units are specified or to the requirements described in the applicable track of Test Methods A1058 if SI units are specified.

18.1如果规定了英寸-磅单位，则应按照试验方法和定义A370的附件A2进行所需的试样和机械试验，如果规定了国际单位制，则应根据试验方法A1058适用轨道中描述的要求进行。
18.2 Specimens shall be tested at room temperature.

18.2试样应在室温下进行测试。
18.3 Small or subsize specimens as described in Test Methods and Definitions A370 or Test Methods A1058 may be used only when there is insufficient material to prepare one of the standard specimens. When using small or subsize specimens, the largest one possible shall be used.

18.3只有当材料不足以制备标准试样时，才能使用试验方法和定义A370或试验方法A1058中所述的小试样或小试样。使用小尺寸或小尺寸试样时，应使用尽可能大的试样。

19. Flattening Test压扁试验

19.1 A section of tube not less than 2 1 ⁄ 2 in. [63 mm] in length for seamless and not less than 4 in. [100 mm] in length for welded shall be flattened cold between parallel plates in two steps. For welded tubes, the weld shall be placed 90° from the direction of the applied force (at a point of maximum bending).During the first step, which is a test for ductility, no cracks or breaks, except as provided for in 19.4, on the inside, outside, or end surfaces shall occur in seamless tubes, or on the inside or outside surfaces of welded tubes, until the distance between the plates is less than the value of H calculated by the following equation:

19.1长度不小于2 1/2英寸[63毫米]（无缝）和长度不小于4英寸[100毫米]（焊接）的管段应分两步在平行板之间冷压平。对于焊接管，焊缝应与施加力的方向成90°（在最大弯曲点）。在第一步，即延展性试验期间，无缝管或焊接管的内表面或外表面不得出现裂纹或断裂，除非19.4中另有规定，直到板之间的距离小于由以下方程式计算的H值：

where:
  H = distance between flattening plates, in. [mm],平板之间的距离，英寸[mm]，
  t = specified wall thickness of the tube, in. [mm],管的指定壁厚，英寸[mm]，
  D = specified outside diameter of the tube, in. [mm], and管的指定外径，英寸[mm]，以及
  e = deformation per unit length (constant for a given grade of steel: 0.07 for medium-carbon steel (maximum specified carbon 0.19 % or greater), 0.08 for low alloy steel, and 0.09 for low-carbon steel (maximum specified carbon 0.18 % or less)).单位长度变形（给定钢种的常数：中碳钢为0.07（最大规定碳含量0.19%或更高），低合金钢为0.08，低碳钢为0.09（最大指定碳含量0.18%或更低））。

During the second step, which is a test for soundness, the flattening shall be continued until the specimen breaks or the opposite walls of the tube meet. Evidence of laminated or unsound material, or of incomplete weld that is revealed during the entire flattening test shall be cause for rejection.

在第二步，即坚固性测试中，应继续压平，直到试样断裂或管子的相对壁相遇。在整个压扁试验过程中发现的层压或不牢固材料或不完整焊缝的证据应作为拒收的理由。
19.2 Surface imperfections in the test specimens before flattening, but revealed during the first step of the flattening test, shall be judged in accordance with the finish requirements.

19.2压扁前试样中的表面缺陷，但在压扁试验的第一步中暴露出来的，应根据光洁度要求进行判断。
19.3 Superficial ruptures resulting from surface imperfections shall not be cause for rejection.

19.3表面缺陷造成的表面破裂不应成为拒收的理由。
19.4 When low D-to-t ratio tubular products are tested,because the strain imposed due to geometry is unreasonably high on the inside surface at the six and twelve o’clock locations, cracks at these locations shall not be cause for rejection if the D to t ratio is less than 10.

19.4当测试低D-t比的管状产品时，由于几何形状在六点钟和十二点钟位置的内表面上施加的应变过高，如果D-t比小于10，则这些位置的裂纹不应成为拒收的原因。

23.1 For tubes 0.200 in. [5.1 mm] and over in wall thickness, either the Brinell or Rockwell hardness test shall be used. When Brinell hardness testing is used, a 10-mm ball with 3000, 1500, or 500-kg load, or a 5-mm ball with 750-kg load may be used, at the option of the manufacturer.

23.1对于壁厚为0.200英寸[5.1毫米]及以上的管子，应使用布氏硬度或洛氏硬度试验。当使用布氏硬度测试时，制造商可以选择使用负载为3000、1500或500kg的10mm球，或负载为750kg的5mm球。
23.2 For tubes less than 0.200 in. [5.1 mm] to and including 0.065 in. [1.7 mm] in wall thickness, the Rockwell hardness test shall be used.

23.2对于壁厚小于0.200英寸[5.1毫米]至0.065英寸[1.7毫米]的管子，应使用洛氏硬度试验。
23.3 For tubes less than 0.065 in. [1.7 mm] in wall thickness, the hardness test shall not be required.

23.3对于壁厚小于0.065英寸[1.7毫米]的管子，不需要进行硬度试验。
23.4 The Brinell hardness test may be made on the outside of the tube near the end, on the outside of a specimen cut from the tube, or on the wall cross section of a specimen cut from the tube at the option of the manufacturer. This test shall be made so that the distance from the center of the impression to the edge of the specimen is at least 2.5 times the diameter of the impression.

23.4布氏硬度试验可在靠近末端的管子外侧、从管子上切下的试样外侧或从管子上切割的试样的壁横截面上进行，由制造商选择。进行此测试时，压痕中心到试样边缘的距离应至少为压痕直径的2.5倍。
23.5 The Rockwell hardness test may be made on the inside surface, on the wall cross section, or on a flat on the outside surface at the option of the manufacturer.

23.5根据制造商的选择，洛氏硬度试验可以在内表面、壁横截面或外表面的平面上进行。
23.6 For tubes furnished with upset, swaged, or otherwise formed ends, the hardness test shall be made as prescribed in

23.6对于带有镦粗、型锻或其他成型端部的管子，应按照
23.1 and 23.2 on the outside of the tube near the end after the forming operation and heat treatment.

23.1和23.2在成形操作和热处理后靠近管端的管外侧。
23.7 For welded or brazed tubes, the hardness test shall be made away from the joints.

23.7对于焊接或铜焊管，硬度试验应远离接头。
23.8 When the product specification provides for Vickers hardness, such testing shall be in accordance with Test Method E92.

23.8当产品规范规定了维氏硬度时，此类测试应符合测试方法E92。

24. Hydrostatic Test水压试验

24.1 Except as provided in 24.2 and 24.3, each tube shall be tested by the manufacturer to a minimum hydrostatic test pressure determined by the following equation:

24.1除24.2和24.3中规定的情况外，制造商应按照以下方程式确定的最小静水压试验压力对每根管子进行测试：

where:
  P = hydrostatic test pressure, psi or MPa,静水压试验压力，psi或MPa，
  t = specified wall thickness, in. or mm, and规定的壁厚，英寸或毫米，以及
  D = specified outside diameter, in. or mm.指定外径，英寸或毫米。

24.1.1 The hydrostatic test pressure determined by Eq 3 shall be rounded to the nearest 50 psi [0.5 MPa] for pressure below 1000 psi [7 MPa], and to the nearest 100 psi [1 MPa] for pressures 1000 psi [7 MPa] and above. The hydrostatic test may be performed prior to cutting to final length, or prior to upsetting, swaging, expanding, bending or other forming operations, or both.

24.1.1对于低于1000 psi[7 MPa]的压力，方程式3确定的静水压试验压力应四舍五入到最接近的50 psi[0.5 MPa]，对于1000 psi[7MPa]及以上的压力，应四舍五入到最靠近的100 psi[1 MPa]。静水压试验可以在切割到最终长度之前进行，也可以在镦粗、型锻、膨胀、弯曲或其他成形操作之前进行，或者两者兼而有之。
24.2 Regardless of the determination made by Eq 3, the minimum hydrostatic test pressure required to satisfy these requirements need not exceed the values given in Table 7. This does not prohibit testing at higher pressures at manufacturer’s option or as provided in 24.3.

24.2无论方程式3如何确定，满足这些要求所需的最小静水压试验压力都不需要超过表7中给出的值。这并不禁止制造商选择或按照24.3的规定在更高的压力下进行测试。

TABLE 7 Hydrostatic Test Pressures

24.3 With concurrence of the manufacturer, a minimum hydrostatic test pressure in excess of the requirements of 24.2 or 24.1, or both, may be stated on the order. The tube wall stress shall be determined by the following equation:

24.3经制造商同意，订单上可注明超过24.2或24.1或两者要求的最小静水压试验压力。管壁应力应通过以下方程式确定：

where:
  S = tube wall stress, psi or MPa, and all other symbols as管壁应力，psi或MPa，以及所有其他符号
defined in 24.1.1.定义见24.1.1。

24.4 The test pressure shall be held for a minimum of 5 s.

24.4试验压力应保持至少5秒。
24.5 If any tube shows leaks during the hydrostatic test, it shall be rejected.

24.5如果任何管子在静水压试验期间出现泄漏，则应拒收。
24.6 The hydrostatic test may not be capable of testing the end portion of the pipe. The lengths of pipe that cannot be tested shall be determined by the manufacturer and, when specified in the purchase order, reported to the purchaser.

24.6水压试验可能无法测试管道的端部。无法测试的管道长度应由制造商确定，并在采购订单中规定时报告给买方。