利用Gleeble-1500D型热／力模拟试验机，采用热膨胀法测定了不同铌含量低碳含铌微合金钢在不同冷速下的相变点，研究了奥氏体连续冷却时的相变行为及铌含量和冷却速率对该钢相变组织与硬度的影响。结果表明：随着铌含量和冷速的提高，γ→α相变温度降低，相变组织变得复杂，显微硬度升高；铌含量较低（小于0．024%，质量分数）的钢在冷速较低（3℃·S^-1）时，显微组织为较粗大的铁素体和少量珠光体，冷速提高后主要是由尖角形、多边形铁素体和贝氏体组成的混合组织；铌含量较高（0．06％）的钢在高冷速（50℃·S^-1）下出现了针状铁素体组织。
The transformation temperatures at different cooling rates of low-carbon Nb-bearing microalloyed steels with different Nb contents were obtained by thermal dilation method using Gleeble-1500D thermo-mechanical simulator. The transformation behavior of austenite during continuous cooling and the effects of Nb content and cooling rate on transformation microstructure and hardness were studied. The results show that the γ→α transformation temperature lowered, the microstructure became more complex and the microhardness increased with the increase of Nb content and cooling rate. The microstructure of the steel with low Nb content （〈0. 024wt%） was composed of coarser ferrite and minor pearlite at slow cooling rate of 3℃ · s^-1 , the sharp-angle shaped and polygon shaped ferrite as well as banite were got at higher cooling rates. The acicular ferrite was got at higher cooling rate （50 ℃ · s^-1） in the higher Nh content （0.06wt%）steel.
参考文献
| [1] | 刘清友,董瀚,孙新军,陈红桔,梁小恺,翁宇庆,李德刚,王雪莲,包春林,贾会昌,董瑞峰.CSP工艺中含Nb钢的混晶问题及改善方法[J].钢铁,2003(08):16-19. |
| [2] | 王庆敏,赵海洋,王立坚,田士平.含Nb微合金低碳钢奥氏体连续冷却转变行为[J].热加工工艺,2010(06):25-28. |
| [3] | 衣海龙,杜林秀,王国栋,刘相华.含铌微合金低碳钢的连续冷却过程的相变[J].东北大学学报（自然科学版）,2005(08):743-746. |
| [4] | 张红梅,王国栋,刘相华.形变热处理工艺对低碳微合金管线钢晶粒细化的影响[J].机械工程材料,2002(01):13-15,34. |
| [5] | 冯光宏,杨钢,李岩.低碳锰铌钢的工艺制度与组织性能的关系[J].钢铁研究,1999(03):24-27. |
| [6] | Seung Chan Hong;Sung Hwan Lim;Hyun Seon Hong .Effects of Nb on strain induced ferrite transformation in C-Mn steel[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2003(1/2):241-248. |
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