X65MS酸性服役管线钢焊接性研究

摘要

According to the phase-transition temperature of material under different cooling rate, the SH-CCT curve of X65MS sour resistant pipe was set up by utilizing Gleeble 3500 thermo-mechanical simulator. Combined with microstructure and microhardness measurement, the weldability of X65MS pipeline steel was analyzed. The test results showed that HAZ softening phenomenon appearance during the submerged arc welding X65MS pipeline steel for sour service. The cooling temperature after welding up to 20℃/s can improve HAZ softening, and the HAZ structure is granular bainite.%利用Gleeble 3500热模拟试验机，根据测得不同冷却速度下材料的相变温度，建立了X65MS耐酸管的SH-CCT曲线。结合微观组织和显微硬度测试，分析了X65MS管线钢焊接性。试验结果表明： X65MS酸性服役管线钢制管埋弧焊时存在热影响区软化现象，将焊后冷却速度提高至20℃/s可以改善热影响区软化，此时焊接热影响区组织为粒状贝氏体。