ASTM A420/A420M specification covers wrought carbon steel and alloy steel pipe fittings of seamless and welded construction for use in pressure piping and pressure vessel service at low temperatures. Materials shall consist of forgings, bars, plates, seamless or fusion welded tubular products with filler metal added, and shall be produced by open-hearth, basic-oxygen, or electric-furnace process. Forging or forming operations shall be performed by one or a combination of two or more of the following procedures: hammering, pressing, piercing, extruding, upsetting, working, bending, fusion-welding, or machining. All welding shall be completed prior to the austenitizing heat treatment, which shall be executed in the normalized, normalized and tempered, annealed, or quenched and tempered conditions. Steel specimens shall conform to required values of chemical composition, tensile strength, yield strength, elongation, wall thickness, and Charpy V-notch impact value. All fusion-welded butt joints shall undergo radiographic examination, while hydrostatic testing of fittings is not required in this specification. Repair welding shall be permissible for parts made to dimensional standards.

ASTM A420/A420M规范涵盖了用于低温压力管道和压力容器服务的无缝和焊接结构的锻造碳钢和合金钢管配件。材料应由锻件、棒材、板材、添加了填充金属的无缝或熔焊管状产品组成，并应通过平炉、碱性氧气或电炉工艺生产。锻造或成形操作应通过以下一种或两种或多种程序的组合进行：锤击、压制、刺穿、挤压、镦粗、加工、弯曲、熔焊或机加工。所有焊接应在奥氏体化热处理之前完成，该热处理应在正火、正火和回火、退火或淬火和回火条件下进行。钢试样应符合化学成分、抗拉强度、屈服强度、伸长率、壁厚和夏比V型缺口冲击值的要求值。所有熔焊对接接头应进行射线检测，而本规范中不要求对配件进行静水压试验。对于按照尺寸标准制造的零件，应允许进行补焊。

Chemical Composition (%) of ASTM A420的化学成分（%）

Notes:

*For grade WPL6, the limit for Columbium may be increased up to 0.05% on heat analysis and 0.06% on product analysis.

*Fittings of WPL3 made from plate or forgings may have 0.90 % max manganese.

*Fittings of WPL8 made from plate may have 0.98 % max manganese.

笔记：

*对于WPL6级，钶的限量在热分析中可提高至0.05%，在产品分析中可增加至0.06%。

*由板材或锻件制成的WPL3配件的最大锰含量为0.90%。

*由板材制成的WPL8配件的最大锰含量为0.98%。

Mechanical properties of ASTM A420的机械性能

*All the elongation values are on the basis of standard round specimen, or small proportional specimen, min % in 4 D.

ASTM A234 is Standard Specification for steel pipe fittings includes carbon and alloy steel material for moderate and high temperature services.

*所有伸长率值均基于标准圆形试样或小比例试样，在4D内最小为%。

ASTM A234是适用于中高温环境的钢管配件的标准规范，包括碳钢和合金钢材料。