热输入对WEL-TEN780A高强钢焊接热影响区断裂性能和组织的影响  

INFLUENCE OF HEAT INPUT ON THE HAZ FRACTURE TOUGHNESS AND MICROSTRUCTURE OF WEL-TEN780A HIGH STRENGTH STEEL

作　　者：周志良[1] 谢明[1] 林文君[1] 刘志臣 

机构地区：[1]大连铁道学院,116028 [2]齐齐哈尔车辆厂,161000

出　　处：《焊接》1999年第10期8-11,共4页Welding & Joining

基　　金：铁道部基金资助项目。

摘　　要：研究了焊接热输入对WEL-TEN780A高强钢热影响区(HAZ)断裂性能的影响。结果表明,通过控制焊接热输入可以获得理想的焊接热影响区断裂性能。控制焊接热输入使得t_(8/5)为10～25s时,CTOD断裂韧性值均大于0.25mm,其断口呈韧窝状;而t_(8/5)等于30s时,CTOD值有所下降,最小值低于0.25mm,试样断口呈解理状;过热区组织粗大,原奥氏体晶界有MA组织析出。采用较小的焊接热输入和较快的冷却速度,有利于提高该类钢焊接接头抵抗脆断的能力。HAZ fracture toughness and microstructure of WEL - TEN780A high strength steel was investigated by using CTOD fracture mechanics test. It was found that the welding heat input affects the CTOD fracture toughness and microstructure of the studied steel HAZ. Controlling heat input i.e. t8/5 in the range of 10-25 s, high CTOD values above0.25 mm were obtained and specimens fractured in ductile mode. Increasing heat input to 30 s of t8/5 deteriorated the HAZ fracture toughness and specimens fractured in cleavage manner. Higher heat input produced unfavorable HAZ microstructure to cause cleavage crack initiation and propagation and therefore decreased HAZ fracture toughness.

关 键 词：热影响区 断裂韧性 热输入 高强度钢 焊接 

分 类 号：TG457.11[金属学及工艺—焊接] TG402