P91大径钢管焊缝热处理质量控制

Quality control of welding seam heat treatment for large diameter P91 steel pipe

对2×350 MW超临界火力发电机组的P91大径钢管焊缝进行热处理。采取分4区控温,合理选择测温点、均匀布置发热体,有效解决了大径管焊缝热处理过程中上下温差大、热处理质量较难控制的难题,焊缝区热处理后的硬度平均值为205-230 HB,显微组织为典型的回火马氏体组织,满足了设计要求。

Weld heat treatment for large diameter P91 steel pipe of 2×350 MW supercritical power generating units in a power plant was conducted.It adopted heat treatment measures of 4 zones temperature control,rational selection in the measure point of temperature and uniform arrangement of heating elements.Then it effectively solved the problem of large temperature deviation between up and down of the pipe diameter during the weld heat treatment and the problem that of quality control.The obtained average value of weld hardness is 205-230 HB and weld microstructure is typical tempered martensite,which meet the design requirements.