摘要
通过微观组织观察和显微硬度测试,研究了预热温度和焊接电流两个工艺参数对4Cr5Mo2V钢表面堆焊层组织性能的影响,并通过堆焊层温度场数值模拟结果揭示了堆焊层组织和性能的演变机理。结果表明:母材未预热处理时,采用70 A的焊接电流对4Cr5Mo2V钢进行堆焊,其熔池的熔宽和熔深分别为7.0和1.5 mm,晶粒长度和宽度分别为10.9和4.0μm;增大焊接电流后,熔池峰值温度的大幅度上升使得熔池尺寸、晶粒尺寸和热影响区宽度进一步增大,从而恶化了堆焊层的性能;预热温度的升高降低了4Cr5Mo2V钢堆焊层在堆焊过程中的冷却速度,导致堆焊层平均硬度逐渐降低,450℃预热后堆焊层平均硬度降低了4.9%,母材仍保持原有的硬度水平,得到了强韧性匹配较高的堆焊层。
Influence of preheating temperature and welding current on microstructure and properties of surfacing layer on 4Cr5Mo2V steel surface was studied through microstructure observation and microhardness testing.The evolution mechanism of the microstructure and properties of the surfacing layer was revealed through numerical simulation results of the surfacing layer temperature field.The results show that when the base material is not preheated,a welding current of 70 A is used to weld 4Cr5Mo2V steel,the width and depth of the weld pool are 7.0 and 1.5 mm,respectively,and the length and width of the grain are 10.9 and 4.0μm,respectively.With the increase of welding current,the peak temperature of weld pool increases greatly,which further increases the size of weld pool,the grain size and the width of heat affected zone,thus deteriorating the performance of the surfacing layer.The increase in preheating temperature reduces the cooling rate of the 4Cr5Mo2V steel surfacing layer during the surfacing,resulting in a gradual decrease in the average hardness of the surfacing layer.After preheating at 450℃,the average hardness of the surfacing layer decreases by 4.9%,while the base material keeps the original hardness level,so the surfacing layer with high strength and toughness matching is obtained.
作者
左鹏鹏
刘骏伟
唐剑
张璐瑶
禚孝儒
金森林
ZUO Peng-peng;LIU Jun-wei;TANG Jian;ZHANG Lu-yao;ZHUO Xiao-ru;JIN Sen-lin(School of Materials Science and Physics,University of Mining and Technology,Xuzhou 221116,China;Zhejiang Qingshan Iron and Steel Co Ltd,Lishui 323903,China;School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212003,China;Shenzhen Institute for Technology Innovation,NIM,Shenzhen 518107,China)
出处
《材料热处理学报》
CAS
CSCD
北大核心
2024年第12期201-210,共10页
Transactions of Materials and Heat Treatment
基金
深圳市自然科学基金重点项目(JCYJ20220818103601003)。
关键词
模具钢
预热温度
焊接电流
温度场
堆焊层
die steel
preheating temperature
welding current
temperature field
surfacing layer
