重复回火对P91钢焊接热影响区高温力学性能的影响

Effect of Repeat Tempering on the High-temperature Mechanical Properties of P91 Steel Welding Heat Affected Zone

对P91管道焊缝进行了不同次数的回火热处理,利用金相观察和高温拉伸试验研究了回火次数对P91管道热影响区组织及高温力学性能的影响。结果表明,经过重复高温回火,P91管道热影响区组织主要为回火索氏体,高温抗拉强度随再回火次数的增多先增大后减小,再回火1次时,其高温抗拉强度达到最大值232.66MPa。

The tempering with different times of P91 steel pipe welds was carded out. Effects of tempering times on the microstructure and high-temperature mechanical properties of P91 pipe heat affected zone were investigated by using metallographic observation and high-temperature mechanical properties test. The results indicate that its microstructure is tempered sorbite after re-tempering at high temperature, while the high temperature tensile strength increases firstly and then decreases with the increase of tempering times. When the P91 pipe was re-tempered once, its maximum high temperature tensile strength reaches 232.66 MPa.