钡处理钢的微观组织和机械性能  

Microstructure and Mechanical Properties of Barium Treated Steels

作　　者：李阳[1] 姜周华[1] 刘杨[1] 

机构地区：[1]东北大学材料与冶金学院,辽宁沈阳110004

出　　处：《东北大学学报（自然科学版）》2007年第1期76-79,共4页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金;上海宝山钢铁集团公司联合资助项目(50174012)

摘　　要：在实验室和现场试验条件下分别采用Si-Ca和Si-Ca-Ba合金处理304 L不锈钢和70钢,在金相和扫描电镜观察与钢材机械性能测定后发现,钡在钢液中是一种强的表面活性元素,可以改变晶粒表面能,使不锈钢铸态组织明显细化,70钢中珠光体片层厚度减小,珠光体形貌呈团簇状趋势分布.残存在钢中的钡含量很小,含钡析出相多处于晶界和相界位置,提高了晶格错配程度,在热处理和变形过程中,阻碍晶界和位错的运动,可以起到强化晶界和钉扎位错的效果,从而提高钢材的机械性能.The 304 L stainless steel and 70 steel were treated by Si-Ca and Si-Ca-Ba alloys in laboratory and industrial test. The results of OM/SEM observations and tests for mechanical properties showed that the as-cast structure of the stainless steel treated by Si-Ca-Ba alloy is refined remarkably, and the lamellar thickness of pearlitic structure in 70 steel decreases with the pearlitic morphology showing clustering distribution because barium can change the surface energy of grains as a strong surface active element. Only a few bit of barium is found in steel and the enrichment of barium-bearing precipitated phase mostly lies on the grain boundary and phase boundary, thus improving the lattice misfit and preventing the movement of grain boundary and dislocation during heat-treatment and deformation. Therefore, the strength and toughness of barium-treated steels can be improved by the effects of intercrystalline strengthening and nailprick dislocation.

关 键 词：微观组织 机械性能 含钡合金 不锈钢 70钢 

分 类 号：TG142.1[一般工业技术—材料科学与工程]