摘要
通过光学显微镜、扫描电子显微镜、透射电子显微镜以及力学分析等方法研究了Nb对高强耐磨钢组织和力学性能的影响,并讨论了含Nb耐磨钢的强韧化机理。结果表明,在200℃回火时,实验用钢展示了较好的力学性能;随着回火温度的提高,实验钢的力学性能逐渐下降。加入少量的Nb元素,一方面在加热过程中抑制了晶粒的长大,另一方面在轧制过程中形变诱导析出NbC析出抑制了晶粒的回复和再结晶,保留了较大的位错密度,在细晶强化、析出强化和位错强化的共同作用下,含Nb钢展示了更为优越的力学性能,并且Nb元素能够抑制渗碳体的形成,防止由于回火脆性造成韧性的大幅下降。
Effect of Nb content on structure-property behavior of high strength wear resistance steel was studied by optical microscope(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM) and mechanical analysis. The strengthening and toughening mechanisms were also discussed. The results show that when tempering at 200 ℃,good mechanical properties for both Nb-free and Nb-bearing steels can be obtained,and then decrease with the increasing of tempering temperature. With the addition of 0. 021% Nb,the grain growth can be retarded during reheating and isothermal holding,and the recovery and recrystalization are also retarded by the precipitation of NbC during rolling process,therefore the higher dislocation density can be reserved. The mechanical properties of Nb-bearing steel are found to be superior to Nb-free steel duo to the small grain size,dispersion strengthening and dislocation strengthening. In addition,the addition of Nb can depress the formation of cementite,the brittle phase in high strength steel,which prevent the toughness deteriorating.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2013年第S2期41-45,共5页
Transactions of Materials and Heat Treatment
基金
国家"863"计划资助项目(2012AA03A508)
中信-CBMM R&D资助项目
关键词
Nb微合金化钢
耐磨钢
析出
力学性能
Nb microalloyed steel
wear resistance steel
precipitation
mechanical properties
