稀土镧对H13模具钢回火稳定性和抗氧化性的影响  

Effect of Lanthanum on Tempering Resistance and Oxidation Resistance of the H13 Die Steel

作　　者：赵帆 周文健 张志豪 ZHAO Fan;ZHOU Wenjian;ZHANG Zhihao(Key Laboratory for Advanced Materials Processing(MOE),Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China;Beijing Laboratory of Metallic Materials and Processing for Modern Transportation,Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]北京科技大学新材料技术研究院,材料先进制备技术教育部重点实验室,北京100083 [2]北京科技大学新材料技术研究院,现代交通金属材料与加工技术北京实验室,北京100083 [3]华中科技大学材料成形与模具技术国家重点实验室,武汉430074

出　　处：《材料导报》2023年第2期124-129,共6页Materials Reports

基　　金：国家自然科学基金(52101118);佛山市核心技术攻关项目(1920001000409);材料成形与模具技术国家重点实验室开放课题(P2021-002)。

摘　　要：本工作研究了稀土镧对H13模具钢在极限服役温度下的回火稳定性和抗氧化性的影响。随着镧元素的质量分数由0%增大至0.570%,H13模具钢在620℃下加热50 h后的硬度降低值先减小后增大,镧含量为0.052%时H13模具钢的回火稳定性最好,这主要是因为碳化物在回火过程中的融合长大受到了抑制。但是,当镧含量达到0.570%时,铁素体的再结晶受到显著抑制,基体组织为粗大的板条状铁素体,导致H13模具钢回火稳定性降低。添加0.052%的镧对长时间加热后的位错密度影响不显著,这说明稀土镧对H13模具钢回火稳定性的影响主要体现在碳化物和铁素体晶粒的演化。另外,随着镧元素的质量分数由0%增大至0.094%,在650℃加热100 h后H13模具钢的氧化层变得更加光滑和致密,氧化层厚度由48.4μm减小至30.6μm。添加镧元素促进了针状氧化物的形成,并减弱了内氧化。In this work,the effect of La contents on tempering resistance and oxidation resistance of H13 die steels was studied at extreme service temperature.With the La content increasing from 0%to 0.570%,the decrement in hardness after heating at 620℃ for 50 h first decreased and then increased.Addition of 0.052%La inhibited the aggregation and growth of carbides and resulted in the highest tempering resistance.However,addition of 0.570%La inhibited the recrystallization of ferrite and resulted in coarser ferrite grains with lath shape,thus reducing the tempering resistance of H13 hot working die steels.The effect of La-microalloying on tempering resistance of H13 hot working die steels was mainly reflected in the evolution of ferrite grains and carbides,because addition of 0.052%La just increased the dislocation density slightly.With the La content increasing from 0%to 0.094%,the oxidation layer of H13 steel after heating at 650℃for 100 h became more smooth and compact,and its depth decreased from 48.4μm to 30.6μm.Moreover,La addition promoted the formation of acicular oxides and weakened the internal oxidation.

关 键 词：模具钢 稀土 镧 回火稳定性 抗氧化性 

分 类 号：TG142.7[一般工业技术—材料科学与工程]