含Ti微合金低碳钢连续冷却过程中组织演变行为  

Transformation behavior of Ti microalloyed low carbon steel during continuous cooling

作　　者：利成宁[1] 袁国[1] 康健[1] 王国栋[1] 

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819

出　　处：《材料热处理学报》2016年第5期76-81,共6页Transactions of Materials and Heat Treatment

基　　金："十二五"国家科技支撑计划项目(2012BAF04B01);国家自然科学基金(51504063)

摘　　要：通过热膨胀法及金相分析法,研究Ti含量为0.015%~0.10%的低碳钢连续冷却条件下组织演变行为,探讨了Ti含量及冷却速率对低碳钢相变行为的影响规律。结果表明,Ti微合金元素具有细化铁素体晶粒尺寸,抑制铁素体相变,促进贝氏体和马氏体相变的作用。当Ti含量由0.015%增加至0.10%时,0.5℃/s下获得的铁素体平均晶粒尺寸可由24.5μm细化至13μm,铁素体相变的冷却速率范围由≤5℃/s缩小至〈1℃/s,马氏体临界冷却速率由40℃/s降低至20℃/s。冷却速率及Ti含量共同决定Ti微合金低碳钢的组织演变行为,特别是对扩散型的相变开始温度具有显著的影响。The transformation behavior of Ti microalloyed low carbon steel during continuous cooling was investigated by thermal dilation method and metallographic analysis,and the effects of Ti content and cooling rate on the transformation were discussed. The results show that Ti microalloying element plays important roles in refining the ferrite grains,suppressing the ferrite transformation and promoting the transformations of bainite and martensite. When the Ti content increases from 0. 015% to 0. 10%,the average grain size of ferrite obtained at 0. 5 ℃ / s decreases from 24. 5 μm to 13 μm,the range of cooling rate for ferrite transformation narrows from lower than 5 ℃ / s to lower than 1 ℃ / s,and the critical cooling rate of martensite transformation reduces from 40 ℃ / s to 20 ℃ / s. The transformation behaviors,especially the starting temperature of diffusion transformation,are governed by the combined effects of Ti content and cooling rate.

关 键 词：Ti微合金低碳钢 TI含量 CCT曲线 组织演变行为 

分 类 号：TG142.3[一般工业技术—材料科学与工程]