摘要
为拓展304LN焊接钢板的应用领域,对304LN焊接钢板在常规回火工艺后采用2℃/min和5℃/min的降温速率进行3轮深冷处理,比较母材区、热影响区、焊缝区在深冷处理前后室温和低温(-196℃)下的冲击韧性和硬度,使用光学显微镜观察各区域显微组织的变化并用能谱仪(EDS)测量元素含量变化。测试结果表明:经深冷处理后304LN焊接钢板各处常温冲击韧性和低温冲击韧性均发生显著增加;常温冲击韧性增长最大值为母材区,2℃/min降温速率下最大可达13.9%;低温冲击韧性增长最大值为热影响区和焊缝区,分别在5℃/min和2℃/min降温速率下最大可达19.0%和19.4%;深冷处理前焊缝区硬度低于母材区,深冷处理后两者硬度相当;深冷处理后可明显看出马氏体相和碳化物的析出,母材区和焊缝区碳化物含量分别由深冷处理前的1.52%和1.45%增加至深冷处理后的1.62%和8.20%,同时Fe元素含量显著增加。
After the conventional tempering process,the 304 LN welded steel plate was subjected to three rounds of cryogenic treatment at a cooling rate of 2℃/min and 5℃/min.The hardness and impact toughness of base metal zone,heat affected zone and weld zone at room temperature and low temperature(-196℃)were tested and compared.Moreover,the changes in the microstructure of each area were observed with an optical microscope and the changes in element content were measured with an energy spectrometer(EDS).Results showed that after cryogenic treatment,the room-temperature impact toughness and low-temperature impact toughness of 304 LN welded steel plate increased significantly.The maximum increase in impact toughness at room temperature was in the base material area,which could reach 13.9%at a cooling rate of 2℃/min.The maximum increase in low-temperature impact toughness was at the heat-affected zone and the weld zone,which could reach 19.0%and 19.4%at a cooling rate of 5℃/min and 2℃/min,respectively.The hardness of the weld zone was lower than that of the base metal zone before the cryogenic treatment,and the hardness of the two zones was equivalent after the cryogenic treatment.The precipitation of martensite phase and carbides could be clearly seen after cryogenic treatment.The carbide content in the base metal zone and weld zone increased from 1.52%and 1.45%before cryogenic treatment to 1.62%and 8.20%after cryogenic treatment,and Fe content increased significantly.
作者
骆文进
王丽英
张银会
卢郁健
LUO Wen-jin;WANG Li-ying;ZHANG Yin-hui;LU Yu-jian(School of Civil Engineering,Chongqing Jianzhu College,Chongqing 400072,China;Department of Architecture and Art,Guangzhou Modern Information Engineering College,Guangzhou 510663,China)
出处
《材料保护》
CAS
CSCD
北大核心
2020年第9期91-95,共5页
Materials Protection
基金
重庆市高等教育教学改革研究项目(203727)
重庆建筑工程职业学院青年研究基金项目(QN2018007)
重庆市教育委员会科学技术研究青年项目(KJQN201904306)资助。
