摘要
对2.5 mm厚BT20钛合金激光焊接接头各区域(包括焊缝和热影响区)的组织特征进行了观察,并测试了焊接接头各区域的显微硬度分布以及室温条件下的接头拉伸、弯曲、疲劳及断裂韧度等力学性能。研究结果表明,焊接接头各区域的微观组织均以“网篮状”马氏体组织为特征,接头各区域显微硬度均高于母材。接头静抗拉强度基本与母材相当,塑性略低于母材。接头中值疲劳寿命与应力水平有很大的关系。在低应力水平下,接头中值疲劳寿命与母材相当,而在高应力水平下,接头中值疲劳寿命远低于母材。接头焊缝金属的断裂韧度显著低于母材,而热影响区断裂韧度则介于母材和焊缝金属之间。
The microstructure in various zones of laser welded joint of BT20 titanium alloy with 2.5mm thickness was observed and the mechanical properties,such as the microhardness,the tensile and the bending properties,the fatigue life and the fracture toughness of the joint at room temperature,were tested.The microstructure in various zones consists of martensite and the microhardness of the joint is higher than that of the base metal.The tensile strength of the joint is equal to that of the base metal and the ductility of the joint is slightly lower.The stress level has an important influence on the fatigue life of the joint,which is equal to that of the base metal at low stress level but obviously lower at high stress level.The fracture toughness of the weld metal is lower than that of the base metal and the fracture toughness of heat-affected zone(HAZ) is intervenient between those of weld metal and base metal.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2006年第2期69-72,76,共5页
Transactions of The China Welding Institution
关键词
钛合金
激光焊接
组织
力学性能
titanium alloy
laser penetration welding
microstructure
mechanical property
