铬对高蠕化率中硅钼蠕铁组织和高温抗拉强度的影响  

Effect of chromium on the microstructure and high temperature tensile strength of medium silicon-molybdenum vermicular iron with high creep rate

作　　者：解骐鸣 曲迎东[1] 高民强 李广龙[1] 

机构地区：[1]沈阳工业大学,沈阳110870

出　　处：《中国铸造装备与技术》2016年第3期24-26,共3页China Foundry Machinery & Technology

基　　金：国家自然科学基金资助项目(51274142);沈阳市科技攻关项目(F13-036-2-00)

摘　　要：高蠕化率中硅钼蠕墨铸铁在急冷条件下的耐热疲劳性能优良,但高温抗拉强度较低,通过在高蠕化率中硅钼蠕铁中添加铬,研究铬对高蠕化率中硅钼蠕墨铸铁的高温抗拉强度的影响。研究结果表明,随铬加量的增加,导致珠光体和碳化物的含量增加,使基体在共析转变过程中析出的石墨量减少,导致基体中蠕虫状石墨量减少,在800℃条件下的抗拉强度得到明显的提升。含铬量0.71%的中硅钼蠕铁抗拉强度比不含铬的普通中硅钼蠕铁提升了12%。铬含量的增加,使铬在铁液凝固过程中形成的偏析量增加,促进碳化物形成,同时在碳化物周围铬的富集区增加,珠光体和碳化物并存出现。Medium silicon-molybdenum vermicular iron with high creep rate has good thermal fatigue performance under the condition of rapid cooling, but the high temperature tensile strength is low. Some experiments were conducted to research the effect of chromium on the high temperature tensile strength of medium silicon-molybdenum vermicular iron with high creep rate through adding chromium to medium siliconmolybdenum vermicular iron with high creep rate in this paper. The results show that the graphite content in the medium silicon-molybdenum vermicular iron decreases. With the increase of chromium content, the pearlite and carbide content increases. Cr plays a role in strengthening the matrix, meanwhile carbide also slows the softening of materials at high temperatures. The tensile strength at 800 ℃ increases significantly, and the tensile strength of medium silicon-molybdenum vermicular iron by adding 0.71% Cr is improved 12% than that of ordinary medium silicon-molybdenum vermicular iron. With the increase of chromium content, chromium segregation amount increases in the process of iron liquid solidification, which promotes carbide formation. At the same time, the area of the chromium enrichment increases.

关 键 词：中硅钼蠕铁 铬 高温抗拉强度 

分 类 号：TG250[金属学及工艺—铸造]