摘要
采用光学显微镜、扫描电镜、纳米力学探针、透射电镜等技术对不同Si含量(0.03%和1.077%)的DP600级别热轧双相钢单向拉伸过程组织特征进行研究,分析了Si含量对相同工艺条件下双相钢显微组织特征,以及塑性变形过程中强化相与基体协调变形行为的影响。结果表明:Si作为一种铁素体形成元素,能够增加铁素体的形核率,具有细化铁素体晶粒的作用,可增加铁素体体积分数,分割并细化马氏体。Si含量的增加促进了C元素向马氏体富集,提升了单位体积马氏体的碳含量,使部分板条马氏体转变为孪晶马氏体,增加了马氏体硬度。由于Si对铁素体的净化作用,高Si实验钢中位错在铁素体中滑移时不易受到碳化物的钉扎作用。因此在相同工艺条件下,Si含量的增加可以提高双相钢的抗拉强度,提高硬度,降低屈强比。
Microstructure characteristics during uniaxial tensile process of DP600-level hot rolled dual-phase steel with different Si content（ 0. 03 % or 1. 077%） was studied by means of optical microscope,scanning electron microscope,nano-micro-probe mechanical system,and transmission electron microscope. Effect of Si content on microstructure characteristics of dual-phase steel under the same process conditions,and coordinate deformation behavior of reinforced phases and matrix during the plastic deformation process was analyzed. The results show that as a kind of elements forming ferrite,Si can increase the rate of nucleation and volume fraction the ferrite,and refine the grain size of ferrite,and cause the division and refined of martensite. The increase of Si content promotes the C element enrichment to martensite,increases the carbon content of martensite within unit volume,makes part of lath martensite transform to twin martensite,and the hardness of martensite increases. Because of the purification effect of Si on ferrite,the dislocation of high Si experimental steel is not vulnerable to the pinning effect of carbide when slipping in ferrite. As a result,under the same process conditions,the increase of Si content can improve tensile strength and hardness,and reduce the yield ratio of the dual-phase steel.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2015年第9期103-108,共6页
Transactions of Materials and Heat Treatment
基金
中央高校基本科研业务费专项资金(FRF-TP-12-046A)
北京高校"青年英才计划"(YETP0355)
关键词
DP600热轧双相钢
微观组织
显微硬度
位错
析出碳化物
DP600 hot rolled dual phase steel
microstructure
microhardness
dislocation
precipitation carbides
