DH36钢水下摩擦柱塞焊缺陷及力学性能

Defects and mechanical properties of underwater friction hydro pillar processing on DH36 steel

对DH36结构钢进行25 mm孔深水下摩擦柱塞焊工艺试验,焊后分析和测试了接头的宏观形貌、焊接缺陷、显微硬度、拉伸以及冲击性能。研究结果表明,水下摩擦柱塞焊在塞孔底端拐角处容易出现未焊合缺陷。通过优化塞孔塞棒形状、焊接参数可以获得无缺陷水下焊接接头;接头硬度沿着塞孔横向呈典型的"M"形分布,焊缝发生明显的硬化倾向,最高硬度可达410 HV;水下焊接接头的抗拉强度最高可达母材的96%,-20℃冲击吸收功可达62 J。

Underwater friction hydro pillar processing（FHPP）experiments with 25 mm repairing depth were conducted for DH36 steel. The welds macro morphology, welding defects, microhardness,tensile and charpy impact properties were measured, respeetively.All the results indicate invalid-joining defects are easily presented in the bottom transition zone in underwater FHPP joints.Defect-free underwater FHPP joints for 25 mm depth tapered hole with optimized hole/plug shape and welding parameters could be obtained. The hardness distribution of the joints is characterized with the typical ＂M＂ appearance.The hardening tendency of FHPP weld is obvious and tile highest hardness value can reach 410 HV.The highest tensile strength of underwater weld joints couhl reach 96% of base materials and eharpy impact value could reach 62 J at -20℃.