摘要
通过定向凝固实验研究了易切削钢中硫化物的生成过程,并建立了枝晶臂间距、硫化物的平均直径与凝固条件之间的关系.实验结果表明:随着温度梯度和拉速的增大,MnS的平均直径减小,数量增多;定向凝固过程中硫化物的完全析出温度大约在固相线温度下100℃左右,MnS形态的改变,主要受其组成元素的活度影响,即MnS形态的改变受其界面自由能的影响;对定向凝固实验中钢的枝晶臂间距、硫化物的平均直径与凝固条件的关系进行了拟合,拟合结果与前人研究结果相吻合.
The formation behavior of sulfides in free-cutting steel was investigated under unidirectional solidification.The relations of the dendrite arm spacing and sulfides' average diameter to solidification conditions were established.Experimental results show that the average diameter of MnS inclusions decreases with increasing temperature gradient around the solid/liquid zone and casting speed,but the number of MnS inclusions increases.The complete precipitation temperature of MnS is about 100 ℃ lower than the solidus temperature.The morphological changes of MnS are mainly effected by the activities of constituent elements,in other words,they are mainly influenced by interfacial energy.The relations of the dendrite arm spacing and sulfides' average diameter to solidification conditions were regressed,and the regression results are basically in agreement with the ones of previous researchers.
出处
《北京科技大学学报》
EI
CAS
CSCD
北大核心
2012年第2期118-124,共7页
Journal of University of Science and Technology Beijing
基金
国家自然科学基金资助项目(51174020)
北京市教育委员会共建项目专项资助课题
关键词
易切削钢
夹杂物
硫化锰
枝晶
定向凝固
free-cutting steel
inclusions
manganese sulfide
dendrites
unidirectional solidification