激光焊接HR-2抗氢不锈钢的性能及组织

为研究HR-2抗氢不锈钢的激光焊接性,对焊接接头的力学性能、试样断口扫描电镜形貌、焊缝金相组织及焊缝内气孔的形貌与成分进行了试验与分析.结果表明,激光焊接HR-2抗氢不锈钢,虽然焊接接头的抗拉强度有所升高,断面收缩率和缺口冲击韧性值有所降低,但试样的微观断裂机制与母材一样是按微坑聚集型的韧性断裂方式进行的,表明焊接接头仍然具有较好的韧塑性；焊缝中未出现明显的合金元素烧损或过多的氧化及脱氧产物,焊缝热影响区很窄,与基体的结合界面良好；激光深熔焊接HR-2抗氢不锈钢,焊缝中除了容易出现常见的析出性气孔和反应性气孔外,更容易出现激光焊接所特有的小孔型气孔.

Metallographic structure and properties analysis of welded joint in HR-2 hydrogen,resistant stainless steel by laser welding

The weldability of HR-2 hydrogen,resistant stainless steel(HRSS) was assessed using laser beam,the mechanical properties and SEM fracture morphologies of welded joint,the metallographic microstructure,the morphology and composition of weld porosity were analyzed.The results showed that the tensile strength of welded joint of the HR-2 HRSS by laser welding was up to 755 MPa,even higher than the base metal,while the contraction of cross sectional area and the impact toughness relatively decreased.The fracture mechanism with congregated microporosities,the same with that of the base metal,showed that the welded joint still had good toughness.There were no obvious burning loss of alloying elements,overfull oxid and de,oxid in the weld area.The heat,affected zone was narrow,bonding with the base metal favorably.When the HR-2 HRSS was welded by laser deep penetration welding,not only the reaction blowhole and precipitating gas hole were prone to appear in weld,but also the specific "key hole" type of porosity to laser welding more likely to occur.