正火处理对贝氏体钢辙叉铝热焊接头性能和组织的影响  

Effect on properties and microstructure of bainitic steel crossing joint with thermit welding by normalizing

作　　者：史晓波[1] 张福成[1] 张明[1] 王明明[1] 郑春雷[2] 

机构地区：[1]燕山大学亚稳材料制备技术与科学国家重点实验室,秦皇岛066004 [2]燕山大学材料科学与工程学院,秦皇岛066004

出　　处：《焊接学报》2015年第6期9-13,18,共6页Transactions of The China Welding Institution

基　　金：国家杰出青年科学基金资助项目(50925522)

摘　　要：利用Gleeble-3500试验机模拟了贝氏体钢辙叉铝热焊热影响区各位置的热循环过程,研究了焊后正火工艺对热影响区性能与组织的影响.热模拟结果表明,铝热焊后对接头进行900℃的正火处理,可以使焊接热影响区重新转变为贝氏体组织,提高了冲击韧性并改善硬度分布均匀性,强度值也达到或接近母材水平.根据热模拟试验结果,对贝氏体钢辙叉和U75V钢轨进行了实际的铝热焊接.结果表明,900℃火焰加热正火处理后,焊缝及热影响区软化区的硬度和抗拉强度值均有明显提高,这对提高焊接接头的使用寿命有重要作用.The properties and microstructure of normalized thermit welding heat-affected zone（ HAZ） of bainitic steel crossing were investigated,by simulating different thermal curves in HAZ with a Gleeble-3500 thermal simulator. The simulated results show that the bainite structure can be regained in the thermit welding HAZ by 900 ℃ normalizing. After normalizing,the toughness is improved,the hardness is more uniform,and the tensile strength is reached closely to the level of base metal.Based on the thermal simulated result,bainitic steel crossing and U75 V rail were welded by thermit welding. The results showed that,the hardness and tensile strength of the weld and soft zone in HAZ were significantly improved when the joint was normalized at 900 ℃,which was very important to the life of the joint.

关 键 词：贝氏体钢 辙叉 铝热焊 热模拟 

分 类 号：TG407[金属学及工艺—焊接]