碳含量对冷作强化非调质钢力学性能的影响  

Effect of Carbon Content on Mechanical Properties of Cold Hardening Microalloyed Steel

作　　者：马晓平[1] 惠卫军[1] 刘春明[2] 于同仁[3] 孙维[1] 

机构地区：[1]钢铁研究总院结构材料研究所,北京100081 [2]东北大学材料与冶金学院,辽宁沈阳110006 [3]马鞍山钢铁股份有限公司,安徽马鞍山243000

出　　处：《金属热处理》2006年第12期29-32,共4页Heat Treatment of Metals

基　　金：国家高技术发展计划项目(2003AA331030)

摘　　要：采用3种不同碳含量的钒微合金化非调质钢MFT8，在5％-50％的减面率范围内进行冷拔，研究了冷拔前后的力学性能变化。结果表明，随着碳含量的减少，铁素体含量增加，强度和加工硬化率降低，塑性升高，因而变形抗力降低，临界压缩比升高。在保证强度的基础上，降低碳含量有利于改善钢的强韧性和冷加工性能。冷拔减面率达到γe之后，由于鲍辛格效应，试验钢的压缩真应力下降。随着碳含量的降低，压缩真应力降低的幅度变大，且开始下降所需的减面率γe降低。超过γe，由于加工硬化率增大，压缩真应力又重新上升。因此，最佳减面率受碳含量的影响，应该在保证强度的条件下选取鲍辛格效应较大，而加工硬化率没有明显上升的阶段。The cold-drawn reductions varying from 5% to 50% were applied on three kinds of vanadium microalloyed steels MFT8 with different carbon content, and their mechanical properties were studied. The results show that with the decrease of carbon content, the amount of ferrite increases, while its strength and work-hardening exponent decrease, and ductility is improved. Therefore the compression flow stress decreases, and the critical compression limit increases. With the precondition of required strength, it＇ s advantageous for improving the comprehensive properties of steel MFT8 to low- er its carbon content. Because of Bauschinger effect, the compression flow stress begins to decrease when the cold-drawn reduction exeeeds a certain value γe. The decrease of compression flow stress becomes more significant and its critical value γ3 decreases with the decrease of carbon content. When the cold-drawn reduction exceeds γe, the compression flow stress begins to increase again because of the increase of work-hardening exponent. Therefore, with the precondition of required strength, the optimized cold-drawn reduction is affected by carbon content and should be chosen at which the Bauschinger effect is significant and the work-hardening exponent is relatively small.

关 键 词：冷作强化非调质钢 碳含量 力学性能 鲍辛格效应 

分 类 号：TG142.41[一般工业技术—材料科学与工程]