当MDMT低于-196℃时，是不是允许埋弧焊

mrmalcolm

ASME规范“当MDMT低于-196℃时，焊接方法限于手工电弧焊SMAW，熔化极气体保护焊GMAW，埋弧焊SAW，等离子弧焊PAW，和钨极气体保护焊GTAW ”。然而在某文献看到一句话 “对于最低设计温度低于-196℃的容器，只能采用手工电弧焊(SMAW)熔化极气体保护焊(GTAW)和熔化极氙弧焊(GMAW)不允许采用埋弧自动焊(SAW)。这是由于埋弧自动焊的热输入高,而奥氏体钢的导热性差,在焊接过程中,熔池过热晶粒粗大,导致超低温韧性降低,难以保证超低温性能要求。为此,依靠焊工的操作技术保证焊缝质量的手工电弧焊和钨极氙弧焊制作液氢容器。”
不知道MDMT低于-196℃时，是不是允许埋弧焊

myyeh

ASME VIII-1 UHA-51(a)(3)
(3) When the MDMT is colder than −320°F (−196°C), production welding processes shall be limited to shielded metal arc welding (SMAW), flux cored arc welding (FCAW), gas metal arc welding (GMAW), submerged arc welding (SAW), plasma arc welding (PAW), and gas tung-sten arc welding (GTAW). Each heat, lot, or batch of filler metal and filler metal/flux combination shall be pre﹗se tested as required by (f)(4)(-a) through (f)(4)(-c). Exemp-tion from pre﹗se testing as allowed by (f)(4)(-d) and (f)(4)(-e) is not applicable. Toughness testing shall be performed as specified in (-a) or (-b) below, as appropriate.

mrmalcolm

myyeh 发表于 2023-10-15 08:27
ASME VIII-1 UHA-51(a)(3)
(3) When the MDMT is colder than −320°F (−196°C), production ...

谢谢，ASME条文是不禁止。文献“对于最低设计温度低于-196℃的容器，只能采用手工电弧焊(SMAW)熔化极气体保护焊(GTAW)和熔化极氙弧焊(GMAW)不允许采用埋弧自动焊(SAW)。这是由于埋弧自动焊的热输入高,而奥氏体钢的导热性差,在焊接过程中,熔池过热晶粒粗大,导致超低温韧性降低,难以保证超低温性能要求。为此,依靠焊工的操作技术保证焊缝质量的手工电弧焊和钨极氙弧焊制作液氢容器。  ”这个描述是不准确的吗？谢谢