Maximum exemption thickness of post weld heat treatment for pressure vessels

doi:10.13251/j.issn.0254-6051.2021.11.021

Abstract

Abstract: Engineering practice shows that modern steel quality and welding technology are sufficient to ensure that the structural steel is exempt from post weld heat treatment at larger thicknesses. Relevant thickness is much larger than the provision of maximum exemption thickness of PWHT in the specifications, which originates from engineering experience. In the light of the potential brittle fracture failure of pressure vessel, the method for determining maximum exemption thickness of PWHT was suggested according to the principle of fracture mechanics. Combined with performance data of the Q345R steel, the engineering applicability of the specific thickness values was demonstrated. The results show that the conservative brittle fracture prevention requirements results in the maximum exemption thickness of PWHT in Chinese pressure vessel code being less than that of European and American codes.

Key words: pressure vessel, post weld heat treatment(PWHT), maximum exemption thickness, fracture mechanics

CLC Number:

TG404

Cui Qingfeng, Fang Wunong. Maximum exemption thickness of post weld heat treatment for pressure vessels[J]. Heat Treatment of Metals, 2021, 46(11): 137-142.

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