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規(guī)范涵蓋了用于低溫壓力管道和壓力容器服務(wù)的無縫和焊接結(jié)構(gòu)的鍛造碳鋼和合金鋼管配件。材料應(yīng)由鍛件、棒材、板材、添加了填充金屬的無縫或熔焊管狀產(chǎn)品組成，并應(yīng)通過平爐、堿性氧氣或電爐工藝生產(chǎn)。鍛造或成形操作應(yīng)通過以下一種或兩種或多種程序的組合進(jìn)行：錘擊、壓制、刺穿、擠壓、鐓粗、加工、彎曲、熔焊或機(jī)加工。所有焊接應(yīng)在奧氏體化熱處理之前完成，該熱處理應(yīng)在正火、正火和回火、退火或淬火和回火條件下進(jìn)行。鋼試樣應(yīng)符合化學(xué)成分、抗拉強(qiáng)度、屈服強(qiáng)度、伸長率、壁厚和夏比V型缺口沖擊值的要求值。所有熔焊對接接頭應(yīng)進(jìn)行射線檢測，而本規(guī)范中不要求對配件進(jìn)行靜水壓試驗(yàn)。對于按照尺寸標(biāo)準(zhǔn)制造的零件，應(yīng)允許進(jìn)行補(bǔ)焊。

Chemical Composition (%) of ASTM A420的化學(xué)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.

筆記：

*對于WPL6級，鈳的限量在熱分析中可提高至0.05%，在產(chǎn)品分析中可增加至0.06%。

*由板材或鍛件制成的WPL3配件的最大錳含量為0.90%。

*由板材制成的WPL8配件的最大錳含量為0.98%。

Mechanical properties of ASTM A420的機(jī)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.

*所有伸長率值均基于標(biāo)準(zhǔn)圓形試樣或小比例試樣，在4D內(nèi)最小為%。

ASTM A234是適用于中高溫環(huán)境的鋼管配件的標(biāo)準(zhǔn)規(guī)范，包括碳鋼和合金鋼材料。