冷却速率对高铌微合金钢组织的影响

Influence of Cooling Rate on Microstructures of High-Nb Microalloyed Steel

采用热模拟和组织显微分析方法研究了不同冷却速率对高铌微合金钢组织的影响。结果表明,铌含量高有利于在极低的冷却速率下获得针状铁素体组织,提高冷却速率则能进一步促进针状铁素体转变,并使铁素体板条得到细化。同时,固溶铌有利于针状铁素体的形成,而铌的沉淀析出则不利于针状铁素体的获得。

Influences of different cooling rate on the microstructure of high-Nb microalloyed steel were researched by using thermal simulation and microstructure analysis. The results show that higher Nb content is favorable for obtaining acicular ferrite （AF）. Accelerated cooling promotes AF transformation, and refines lath size of AF. In the meantime, soluble Nb is useful for getting AF while its precipitation exerts negative influence on the AF formation.