HFW焊缝性能优化工艺研究

Research on HFW Weld Performance Optimization Process

通过设计局部焊缝中频感应热处理、局部焊缝+全管体双重中频感应热处理、全管体中频感应加热+热张力减径组合热处理以及在线控制冷却等工艺,研究了J55钢级HFW焊接套管的焊缝性能优化。试验结果表明:焊缝在线局部中频感应热处理、局部焊缝+全管体双重中频感应热处理后空冷或进行控制冷却,可优化J55套管焊缝显微组织分布,细化焊缝组织尺寸,均匀化焊缝硬度分布,提高焊缝冲击韧性,降低沟槽腐蚀敏感系数,但焊缝优化效果低于全管体中频感应加热+热张力减径+在线控制冷却组合工艺。单纯依靠全管体中频感应加热后热张力减径或在线控制冷却工艺对焊缝优化效果并不优于单纯局部焊缝中频感应热处理。

Several heat treatment processes, such as the local weld medium frequency induction heat treatment, local weld＋ full body medium frequency induction heat treatment, full pipe body medium frequency induction heating ＋hot stretch reducing heat treatment, online control cooling and so on were designed to study the performance optimization of HFW weld on J55 grade casing. The test result showed that adopting online local weld medium frequency induction heat treatment, cooling in air or control cooling after local weld＋full body medium frequency induction heat treatment, the microstructure distribution of J55 casing weld is optimized, the weld structure size is refined, the weld hardness distribution is unified, the impact toughness of weld is improved, and the grooving corrosion sensitivity coefficient is reduced. But its weld optimization effect is inferior to full pipe body medium frequency induction heating＋hot stretch reducing＋online control cooling process. And the optimization effect of local weld medium frequency induction heat treatment is better than hot stretch reducing after full pipe body medium frequency induction heating or online control cooling process.