两相区位错增殖对Mn元素配分及低碳钢贝氏体组织的影响

发布时间：2019-02-28 15:27

【摘要】：采用两相区变形-保温-淬火(DIQ)热处理工艺,研究低碳钢两相区变形位错增殖作用下Mn元素配分行为及其对贝氏体组织的影响规律。通过OM、SEM、TEM、EPMA和XRD等手段对组织成分、位错密度、合金元素分布等进行表征。结果表明,变形后的铁素体晶粒和马氏体板条细化、块状马氏体数量减少;位错密度由0.36×10~(14)m~(-2)增加至1.20×10~(14)m~(-2),位错滑移的相互运动提高了空位浓度及间隙溶质原子数量,加速了C、Mn元素在a相与g相中的扩散速率,促进了Mn在两相区的配分效果,C、Mn元素富集量及富集区域增多。采用两相区变形-保温-奥氏体化-淬火-贝氏体区保温-淬火(DIQPB)热处理工艺,残余奥氏体的体积分数由11.5%提高到13.9%,残余奥氏体中的C含量由1.14%提高到1.28%。
[Abstract]:The effect of Mn element distribution and its influence on the bainitic structure of low carbon steel in two-phase region is studied by a two-phase deformation-heat-preserving-quenching (DIQ) heat treatment process. The microstructure, dislocation density and alloy element distribution were characterized by OM, SEM, TEM, EPMA and XRD. The results show that the ferrite grain and the martensite lath after the deformation are refined, the number of the massive martensite is reduced, the dislocation density is increased from 0.36 to 10 to (14) m to (-2) to 1.20 to 10 to (14) m to (-2), the mutual movement of the dislocation slip improves the vacancy concentration and the number of the interstitial solute atoms, and the C is accelerated, The diffusion rate of Mn element in the phase a and g promotes the distribution effect of Mn in the two-phase region, and the concentration of C and Mn elements and the enrichment area are increased. The volume fraction of the residual austenite is increased from 11.5% to 13.9%, and the C content in the residual austenite is increased from 1.14% to 1.28%.
【作者单位】：华北理工大学教育部现代冶金技术重点实验室;中国科学院金属研究所;
【基金】：国家自然科学基金项目No.51574107 河北省自然科学基金项目No.E2016209048和E2017209048 唐山市科技创新团队项目No.15130202C 河北省研究生创新项目No.2017S01~~
【分类号】：TG142.1

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