HT250灰铸铁干熄炉风帽断裂原因分析  

Cause analysis on fracture of gray cast iron HT250 vent-cap of CDQ unit

作　　者：罗扬[1] 崔景毅[1] 王崇云[1] 田文怀[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《金属热处理》2015年第8期188-191,共4页Heat Treatment of Metals

摘　　要：为了考察HT250灰铸铁干熄炉风帽在使用过程中发生断裂的原因,分别利用化学分析法、光学显微镜和布氏硬度计,对断裂后风帽材料的化学成分、微观组织和布氏硬度(HBW)进行了分析、观察和测定,并根据布氏硬度值计算材料的抗拉强度。结果表明,风帽材料中的铁素体含量高于HT250灰铸铁件的要求上限,在风帽非工作面附近的基体组织中,铁素体含量达50%以上;铁素体含量过高导致HT250灰铸铁风帽材料的抗拉强度低于正常,是造成风帽断裂的主要原因。In order to investigate the reason for the fracture of gray cast iron HT250 vent-cap of CDQ （Coke Dry Quenching） unit in service, the chemical composition, microstructure and Brinell hardness （HBW） of vent-cap material after fracture were analyzed by chemical analysis, optical microscope and Brinell hardness tester. And then the tensile strength of vent-cap material was calculated by Brinell hardness. The results indicate that the ferrite amount in vent-cap material is higher than the upper limit requirement of HT250 castings, which even reach over 50% in the matrix microstructure near the non-working surface of vent-cap. It is the main reason for the fracture of vent-cap that excessive ferrite amount leads to tensile strength of HT250 vent-cap material lower than the normal range.

关 键 词：HT250灰铸铁 风帽 断裂 微观组织 

分 类 号：TG115[金属学及工艺—物理冶金]