Novel bake hardening mechanism for bainite-strengthened complex phase steel
Novel bake hardening mechanism for bainite-strengthened complex phase steel
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DOI：
10.1016/j.jmst.2022.08.054
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发表时间：
2022-11
期刊：
影响因子：
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通讯作者：
Hang Yu;Yu Yan;Cheng Zhang;Lijie Qiao
中科院分区：
文献类型：
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作者：
Hang Yu;Yu Yan;Cheng Zhang;Lijie Qiao
在汽车工业中，采用冲压和烤漆工艺来加强部件，这不仅节省了成本，而且还进一步减轻了汽车的车身重量。通过与具有明确烘烤硬化机制且碳含量与CP 980相近的DP 1180的烘烤硬化机制的比较，探讨了CP 980的烘烤硬化机制。通过分析两种钢的烘烤硬化响应和组织变化，发现CP 980的烘烤硬化过程可分为三个阶段。在前两个阶段，碳原子扩散到位错中形成Cottrell气氛钉扎位错，过量的碳原子形成碳团簇或类似于DP1180的低温碳化物钉扎位错。在第三阶段，位错作为碳扩散的快速通道，碳团簇作为前驱体在位错处聚集，逐渐形成细小的珠光体，导致沉淀硬化。这种新的烘烤硬化（BH）机制对于全面了解先进高强度钢（AHSS）的应变烘烤行为至关重要。
In the automobile industry, stamping and paint baking processes are used to strengthen components, and this not only saves costs, but also further reduces the bodyweight of automobiles. In this work, the bake hardening mechanism of the complex phase (CP) steel CP980 was explored by comparing it with that of DP1180, which has a clear bake hardening mechanism and a carbon content similar to that of CP980. By analyzing the bake hardening response and the microstructural changes of the two steels, we found that the bake hardening process of CP980 was divided into three stages. In the first two stages, the carbon atoms diffused into dislocations to form Cottrell atmosphere pinning dislocations, and excess carbon atoms formed carbon clusters or low-temperature carbide pinning dislocations that were similar to DP1180. In the third stage, the dislocation acted as rapid channels for carbon diffusion, and fine cementite gradually formed when the carbon clusters gathered at the dislocations as precursors, resulting in precipitation hardening. This novel bake-hardening (BH) mechanism is crucial for obtaining a comprehensive understanding of the strain-baking behavior of advanced high-strength steals (AHSS).