取消10CrMo910钢厚壁管接头焊后热处理的研究

A STUDY ON CANCELLING OFF POST WELD HEAT TREATMENT(PWHT) OF 10CrMo910 STEEL THICK WALL PIPE JOINT

用深缺口插销法评定１０ＣｒＭｏ９１０钢的冷裂纹和再热裂纹的敏感性，对未经焊后热处理与经过焊后热处理的１０ＣｒＭｏ９１０钢厚壁管接头的性能进行了高温模拟对比试验。试验结果表明：３５ｍｍ厚的１０ＣｒＭｏ９１０钢接头焊前预热１８０～２００℃可防止冷裂纹；１０ＣｒＭｏ９１０钢只有轻微的再热裂纹敏感性，取消焊后热处理的１０ＣｒＭＭ１０钢接头在高温运行过程中不会产生再热裂纹；未经焊后热处理的１０ＣｒＭｏ９１０管接头具有更优良的机械性能。焊后热处理实质上是损失热强性的短时超高温运行过程。作者认为：ｄ＜２７３ｍｍ，δ＜３５ｍｍ的１０ＣｒＭｏ９１０钢管接头取消焊后热处理是可行的。

The susceptibility of 10CrMo910 steel to cooling cracking and stress relief cracking have been investigated by deep notch implant test.The properties of 10CrMo910 steel thick wall pipe joints with and without PWHT have been compared by high temperature test.The results show:1) 10CrMo910 steel pipe joint with thickness 35mm can be prevented from cooling cracking by a 180-200℃ preheating;2)10CrMO910 steel is very lightly sensible to stress relief cracking.Stress relief cracking will not occur in 10CrMo910 steel pipe joints without PWHT during high temperature service.3) Pipe joint without PWHT has higher mechanical properlies.Actually the PWHT is a superhigh temperature operation process reducing hot strength of joints.4) It is feasible to cancel the PWHT of 10CrMo910 steel joints with ≤273mm, δ≤35mm.