Gr.2换热管与管板的TIG封焊工艺研究

Study on TIG Sealing Welding Process of Gr.2 Heat Transter Tube and Tube Plate

针对Gr.1+S30403IV(12 mm+328 mm)爆炸复合管板、Gr.2(φ19.05 mm×2.41 mm)换热管开展TIG封焊工艺研究,对接头进行了外观、渗透、低倍金相和显微硬度检测,设计了封焊接头的轴向拉脱试验,并测定了接头的强度。结果表明,坡口形式对焊缝外观和根部熔合情况有显著影响。采用优化的坡口形式和焊接工艺获得了焊缝外观及渗透检测合格、根部焊透、最小泄漏通道不小于管壁厚度的封焊接头。拉脱试验结果表明封焊接头抗拉强度均高于管材标准要求的抗拉强度。将该工艺应用于实际产品管板封焊后,封焊接头可通过渗透检测、氦检漏及水压测试。

TIG sealing welding experiments of tube plate made of Gr.1+S30403IV(12 mm+328 mm) and Gr.2 heat transfer tube(φ19.05 mm ×2.41 mm) were performed. Visual test(VT), penetration test(PT), low power metallographic examination and microhardness test of the welded joints were conducted. Mock-up test method for the welded joint was designed and strength of the welded joints was tested. It has been verified that the weld groove form has significant influence on the weld appearance and full penetration in the root. The welded joints that can meet the requirements of VT, PT and low power metallographic examination were obtained by using the optimized groove and welding parameters. The mock-up test results show that the tensile strength of the welded joints is higher than the requirement value of the tube. The optimized welding technology was applied to the welding of tube to plate in actual product, the welded joints could meet the requirements of PT, helium leakage detection and hydraulic test.