超高强度300M钢电子束深缝焊接力学性能及破坏机理研究  

Study on Mechanical Properties and Failure Mechanism of Deep Seam Electron Beam Welding of Ultra-high Strength 300M Steel

作　　者：刘星 刘斌[2] 卢智先[2] 赵桐 Liu Xing;Liu Bin;Lu Zhixian;Zhao Tong(School of Aircraft Engineering,Xi’an Aeronautical University,Xi’an 710077,China;School of Aeronautics,Northwestern Polytechnical University,Xi’an 710072,China;Science and Technology on Power Beam Processes Laboratory,Beijing Aeronautical Manufacturing Technology Research Institute,Beijing 100024,China)

机构地区：[1]西安航空学院飞行器学院,西安710077 [2]西北工业大学航空学院,西安710072 [3]北京航空制造工程研究所高能束流加工技术重点实验室,北京100024

出　　处：《航空工程进展》2018年第4期603-610,622,共9页Advances in Aeronautical Science and Engineering

基　　金：西安航空学院通用航空工程技术中心基金(XHY-2016084);西安航空学院校级科研基金(2018KY1226)

摘　　要：超高强度300M钢具有优异的力学性能,广泛应用于飞机起落架。通过静力拉伸、三点弯曲及动态Charpy冲击试验,揭示300M钢电子束深缝焊接的力学性能及破坏机理;对试验后的典型试样进行断口宏观与微观分析,并采用场发射扫描电镜(SEM)对断口形貌进行观察、分析。结果表明:母材与焊接件都出现明显的拉伸塑性段,二者的刚度和强度相差不大,但是焊接件的断裂应变较母材小,焊接件焊缝的韧性略低于母材;焊接件弯曲强度与母材相当,但是破坏时的弯曲变形较母材也有所下降,焊接件的延性较差;在冲击试验中焊接件吸收能量与断裂韧性均低于母材,冲击韧度降低。The ultra-high strength 300M steel is applied in aircraft landing gear because of excellent mechanical properties.The tests of static tensile strength,three-point bending properties and Charpy impact properties are conducted.It reveals the mechanical properties and failure mechanism of electron beam deep seam welding of 300M steel.Macroscopic and microscopic analysis of typical specimens fracture after testing and fractography of weldment fracture surface are investigated by SEM(scanning electron microscope).Results indicate that both parent metal and weldment appear obvious tension plastic behavior,and there is little difference between stiffness and strength.However,the fracture strain and toughness of weldment become weaker compared with the parent metal.The bending strength of weldment is slightly lower than that of the parent metal,and the bending deformation and ductility decline.In Charpy impact test,both absorbed energy and fracture toughness of weldment are lower than parent metal.Thus the impact toughness of weldment decreases.

关 键 词：超高强度300M钢 深焊缝 电子束焊接 拉伸强度 弯曲强度 冲击韧度 

分 类 号：TG404[金属学及工艺—焊接] TG407