摘要
对超厚规格3Cr2Mo模具钢厚度方向进行组织和硬度检测,研究了不同冷速下厚度方向的硬度分布和相变规律。结果表明,导致3Cr2Mo模具钢厚度方向上硬度呈现明显边部高、心部低特征的主要原因是回火索氏体片层间距的差异,边部试样的回火索氏体片层间距较小,而心部试样回火索氏体片层间距略大。当冷速≤0.3℃/s时,有高温珠光体相变+中/低温贝氏体马氏体相变;当冷速≥0.5℃/s时,只有马氏体相变。冷却速度0.5℃/s是发生马氏体转变的临界冷速。由此推断厚板厚度方向的冷速在0.05℃/s浮动,表面冷速不超过0.1℃/s,可获得以珠光体为主的显微组织。
Microstructure and hardness tests of an ultra-thick specification 3Cr2Mo die steel were carried out along the thickness direction.The hardness distribution and phase transformation along the thickness direction with different cooling rates were investigated.The results show that the main reason for the hardness difference along the thickness direction is the difference of the tempered sorbite lamellar spacing,which is smaller in the edge specimens and slightly larger in the heart specimens.When the cooling rate is less than or equal to 0.3℃/s,the high-temperature pearlite transformation and medium-low temperature bainite/martensite transformation are observed.When the cooling rate is greater than or equal to 0.5℃/s,only martensitic transformation occurs.The cooling rate of 0.5℃/s is the critical cooling rate for the martensite transformation.From this,it is inferred that the cooling rate in the thickness direction of the thick plate floats at 0.05℃/s,and the cooling rate of the surface does not exceed 0.1℃/s under which the pearlite microstructure is obtained.
作者
李忠波
袁清
许少普
张涛
陈熙
莫家璇
任杰
Li Zhongbo;Yuan Qing;Xu Shaopu;Zhang Tao;Chen Xi;Mo Jiaxuan;Ren Jie(State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan Hubei 430081,China;Nanyang Hanye Special Steel Co.,Ltd.,Nanyang Henan 474571,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2024年第1期31-38,共8页
Heat Treatment of Metals
基金
国家自然科学基金(52004193)
中国博士后科学基金(2022M710596)。
