铌铪合金喷管搭接结构激光点焊技术研究  

Technical research on laser spot welding of overlap joint of niobium hafnium alloy nozzle

作　　者：张艳桥 张维明 ZHANG Yanqiao;ZHANG Weiming(Xi＇an Space Engine Company Limited, Xi＇an 710100, China)

机构地区：[1]西安航天发动机有限公司,陕西西安710100

出　　处：《火箭推进》2018年第2期71-75,共5页Journal of Rocket Propulsion

摘　　要：某型号铌铪合金喷管加强筋原采用电阻点焊,但存在接头强度低、劳动强度大和焊接效率低等问题。为实现铌铪合金喷管加强筋高质量高效连接,开展了激光点焊工艺试验研究。基于铌铪合金试板激光点焊试验,重点研究了焊点结构设计、焊接工艺参数设计、焊点熔合特征、接头力学性能和接头断裂行为。研究结果表明:7 mm的环形焊点是较为理想的焊点结构,熔合面宽度是决定接头性能和断裂模式的关键因素,而焊接工艺参数直接影响接头熔合面宽度。选择合理的焊接工艺参数,控制焊点熔合面宽度大于0.7 mm,接头断裂模式为母材撕裂或热影响区撕裂,该种断裂模式接头强度较高,接头承载能力不小于8 000 N。最后采用激光点焊工艺实现了铌铪合金喷管高强度的连接,并通过了试车考核。The strengthening ribs for a type of niobium hafnium alloy nozzle was welded by resistance welding in the past, but there were many problems in welding effect, such as low strength, low efficiency and high labour intensity. A study on laser spot welding of strengthening ribs for niobium hafnium alloy nozzle was carried out to improve welding quality. The influence of welding parameters on the mechanical properties, welding spot fusion characteristics and fracture behavior of the joints was studied. The results show that 0. 7 mm diameter ring welding joint is the ideal spot welding structure, the fusion width is the key factor to determine the strength and fracture mode of the joint, and the welding parameters directly af- fects the fusion width. Therefore, When greater than 0. 7 mm fusion width is realized by choosing the ra- tional welding parameter, a higher strength welding joint and the not less than 8 000 N strength of the joint can be achieved. The laser spot welding has been successfully applied to production of niobium haf- nium alloy nozzle.

关 键 词：铌铪合金 激光点焊 焊接工艺参数 断裂行为 

分 类 号：TG456.7[金属学及工艺—焊接]