固溶碳含量对ULC-BH钢烘烤硬化性能的影响

Effect of solid solute carbon on hardening property of ultra-low carbon bake hardened steel

研究了固溶碳含量对ULC-BH钢烘烤硬化性能的影响,测量了不同烘烤时间下的烘烤硬化(BH)值,通过内耗试验分析固溶碳含量变化。结果表明,对试样进行相同预变形、不同时间烘烤硬化处理后,随烘烤时间增加,BH值先快速增大再基本不变最后增大;Snoek峰峰高随烘烤时间的延长而降低,固溶碳含量随时间延长而降低;对于试验钢,常规的烘烤工艺170℃×20 min没有达到最大的BH值,但继续增加烘烤时间BH值提高缓慢。

Effect of solid solute carbon on hardening property of ULC-BH steel was studied in this paper. The BH value of the samples with different aging time were measured and the variation of solid solute carbon amount was analyzed by internal friction test. The result shows that the BH value increases rapidly at first,then basically remains the same and increases slowly at last with the increasing aging time dealing with same pre-strain; The height of Snoek peak and solute carbon amount decreases with the increasing aging time; The BH value does not increase to maximum with the normal baking process 170 ℃ × 20 min,but increases slowly if samples are increased aging time.