| 引用本文: | 计天予,吴晓春.新型热作模具钢SDH3-Mod的热稳机理研究[J].材料科学与工艺,2014,22(6):29-35.DOI:10.11951/j.issn.1005-0299.20140606. |
| JI Tianyu,WU Xiaochun.Thermal stability mechanism of a new hot working die steel SDH3-Mod[J].Materials Science and Technology,2014,22(6):29-35.DOI:10.11951/j.issn.1005-0299.20140606. |
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| 摘要: |
| 为了提高热作模具钢的热稳定性,在H13钢的基础上降V增Mn,设计了新型热作模具钢SDH3-Mod.通过热稳定性实验研究SDH3-Mod和H13在高温服役过程中的硬度变化趋势,结合Johnson-Mehl-Avrami(JMA)方程和透射电子显微镜探讨其高温时效动力学过程及微观组织演变.研究表明:SDH3-Mod在高温下的热稳定性优于H13.620 ℃热稳保温中,SDH3-Mod的基体回复被延迟,碳化物粗化被有效抑制,表现出比H13更加优异的回火抗力,这是由于SDH3-Mod的淬火温度高于H13,马氏体基体中固溶了更多的合金元素,提高了基体的分解温度,从而延迟了马氏体基体的回复；同时,Mn固溶于基体中,降低了高温下碳在铁素体基体中的扩散速率,较好地抑制了碳化物的析出和长大. |
| 关键词: 热作模具钢 热稳 回火抗力 JMA方程 碳化物 |
| DOI：10.11951/j.issn.1005-0299.20140606 |
| 分类号:TG142.45 |
| 基金项目:国家科技支撑计划资助项目(2007BAE51B04). |
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| Thermal stability mechanism of a new hot working die steel SDH3-Mod |
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JI Tianyu, WU Xiaochun
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(School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China)
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| Abstract: |
| To improve the resistance to tempering at high temperature, a newly martensitic hot work die steel (SDH3-Mod) was designed on the basis of H13 with decreasing V and increasing Mn, and the hardness variation, kinetic of thermal aging and their microstructure evolution of SDH3-Mod and H13 were studied at high temperature by Johnson-Mehl-Avrami (JMA) equation and transmission electron microscope (TEM). The results show that SDH3-Mod presents a better resistance to tempering at high temperature. The martensite recovering and carbide coarsening are efficiently inhibited. The softening behavior is evidently delayed in SDH3-Mod, which can be attributed to the α-Fe lattice distortion caused by Mn dissolving into martensite to reduce the diffusion rate of the high temperature carbon in the ferrite matrix, preferably inhibiting carbide coarsening; Meanwhile, the quenching temperature of SDH3-Mod is higher than that of H13, leading to the amount of alloying elements solid solution in the matrix to improve the decomposition temperature of the martensitic matrix. |
| Key words: hot working die steel thermal stability temper resistance JMA equation carbide |
