摘要
对挖泥船泥浆泵叶片用高铬铸铁的热处理工艺进行研究。结果表明,在奥氏体化温度分别为800、900、1000和1100℃下保温3 h后空冷,高铬铸铁硬度随奥氏体化温度的升高先上升后下降,在1000℃淬火时的硬度最高;在1000℃分别保温1、2、3和4 h后空冷,发现保温2 h铸铁的硬度达到峰值;对1000℃×2 h空冷的铸铁试样分别在250℃和450℃回火2 h,发现回火硬度均有小幅提高,但250℃回火的试样冲击性能显著提升,冲击吸收能量达到4.13 J。该叶片材料的最佳热处理工艺为1000℃×2 h空冷淬火+250℃×2 h回火,用该工艺热外理叶片可获得弥散分布的M7C3型碳化物+二次碳化物+回火马氏体基体及少量残留奥氏体组织,抗泥沙磨损能力提高了34.41%。
The heat treatment processes of high chromium cast iron for dredger mud pump blade were studied .The results show that when the high chromium cast iron is austenitized at 800℃, 900℃, 1000℃and 1100℃for 3 h and cooled in air, the hardness first rises and then falls with the austenitizing temperature increasing , it reaches the highest hardness at 1000℃.After holding for 1 h, 2 h, 3 h, 4 h at 1000 ℃respectively, it is indicated that the cast iron is up to maximum hardness when holding for 2 h.When the cast iron quenched at 1000 ℃for 2 h and tempered at 250 ℃and 450 ℃for 2 h separately , it is found that the hardness both increase slightly , but the impact absorbing energy is improved significantly to 4.13 J by tempering at 250 ℃.The optimal heat treatment process for the blade is 1000 ℃× 2 h quenching＋250℃×2 h tempering.The microstructure after heat treatment is dispersed M 7 C3 carbides＋secondary carbides ＋tempered martensite and a small amount of retained austenite .The sand abrasion resistance of blade is increased by 34.41%.
出处
《金属热处理》
CAS
CSCD
北大核心
2013年第10期70-74,共5页
Heat Treatment of Metals
基金
福建省自然科学基金(2013J01202)
关键词
高铬铸铁
热处理
冲击性能
耐磨性
high chromium cast iron
heat treatment
impact property
wear resistance
