国内外焊后热处理标准对新型9％Cr热强钢管道的适用性

摘要

Four domestic and aboard post weld heat treatment (PWHT) standards for 9％ Cr steel pipes are compared and the applicability of these standards is investigated based on field trials of two typical specifications of power plant 9％ Cr steel pipes.The results show that there are large differences in heated band width requirement under different standards.For thin-wall 9％ Cr steel pipes,Chinese,EU and US standards are appropriate.However,guideline from Huaneng is too strict in this case.All four standards cannot meet stringent requirements of temperature difference for thick-wall 9％ Cr steel pipes.It is necessary to improve existing PWHT standards to guide on-site installation of 9％ Cr steel pipes.%通过对4种国内外管道焊后热处理标准推荐加热宽度的比较,结合2种典型规格P91、P92钢管道的局部焊后热处理试验,分析讨论了现有标准对新型9％Cr热强钢管道的适用性.结果表明,现有标准对9％Cr钢管道焊后热处理加热宽度的选取存在较大的差异,对于管壁相对较薄的管道,电力标准、欧盟标准和美国标准推荐的加热宽度比较接近,且可以满足9％Cr钢内、外壁温差控制要求,而华能导则推荐的加热宽度明显偏大:对于厚壁管道,现有标准均难以满足9％Cr钢内、外壁温差的苛刻要求.建议对现有焊后热处理标准进行补充完善,以更好地指导新型9％Cr热强钢管道的现场安装.