从微观组织看中硅钼蠕铁排气管伸长率低的原因  

Reason Analysis on Low Percentage Elongation of Mid-Si-Mo VG Cast Iron Exhaust Tube Casting from Microstructure

作　　者：段汉桥[1] 袁福安[1] 魏伯康[1] 喻平[2] 武炳焕[2] 刘永安[2] 

机构地区：[1]华中科技大学材料学院,湖北武汉430074 [2]东风汽车公司铸造一厂,湖北十堰442048

出　　处：《热加工工艺》2002年第2期40-42,共3页Hot Working Technology

摘　　要：对试生产的中硅钼合金蠕墨铸铁排气管铸件本体伸长率不足的原因进行了显微组织分析。发现 ,在伸长率不足的蠕铁排气管铸件本体的微观组织中 ,沿晶界普遍存在一定数量的钼的碳化物 (Fe,Mo) 3C和复合磷共晶 Fe+(Fe,Mo) 3C+(Fe,Mo) 3P,这是造成铸件伸长率低的根本原因。通过采用随流瞬时孕育 ,能有效地抑制凝固时钼的复合碳化物和复合磷共晶在晶界的生成 。The reasons of low percentage elongation of mid Si Mo vermicular graphite cast iron exhaust tube casting in trial production were analyzed. The result shows that there are some molybdenum carbide (Fe, Mo) 3C and composite phosphide eutectic Fe + (Fe, Mo) 3C + (Fe, Mo) 3P along the grain boundary and this is the essential reason of low percentage elongation of the casting. Using stream inoculation technology can restrain the emergence of the molybdenum carbide and composite phosphide eutectic and increase the percentage elongation of the casting obviously.

关 键 词：微观组织 中硅钼蠕铁 排气管 伸长率 汽车 

分 类 号：U464.134[机械工程—车辆工程] TG255[交通运输工程—载运工具运用工程]