摘要
通过光学显微镜、显微硬度、洛氏硬度及冲击试验,研究了不同淬火温度对Cr23高铬铸铁组织性能的影响,并采用MMW-1立式万能磨损试验机对Cr23的磨损性能进行了测试分析。结果表明:900℃淬火后Cr23高铬铸铁中铸态组织未完全消失;950℃淬火回火后Cr23高铬铸铁的组织为白色的块状、条状碳化物和回火马氏体,二次碳化物弥散分布在基体上;1000℃淬火回火后Cr23高铬铸铁中的组织由回火马氏体、残余奥氏体及长条状碳化物组成,残余奥氏体及回火马氏体都呈现灰黑色。随着淬火温度的增加,高铬铸铁的硬度先升后降,冲击韧性呈下降趋势。高铬铸铁中弥散分布的碳化物可有效提高其耐磨性,回火马氏体基体为碳化物提供支撑,防止其剥落。试样经过950℃淬火+250℃回火后抗磨性最好,较l000℃淬火+250℃回火处理的试样提高了41.4%。
The effects of different quenching temperatures on the microstructure and properties of Cr23 high chromium cast iron were studied by optical microscope,microhardness,Rockwell hardness and impact test.The wear performance of Cr23 high chromium cast iron was tested and analyzed by using a vertical universal wear tester.As cast structure of Cr23 high chromium cast iron has not completely disappeared after quenching at 900℃.After quenching at 950℃and tempering at 250℃,the microstructure of Cr23 high chromium cast iron is white block,strip carbides and tempered martensite,and the secondary carbides are dispersed on the matrix.After quenching at 1000℃ and tempering at 250℃,the microstructure of Cr23 high chromium cast iron is composed of tempered martensite,retained austenite and long strip carbides,and both retained austenite and tempered martensite are gray black.With the increase of quenching temperature,the hardness of high chromium cast iron first increases and then decreases,and the impact toughness shows a downward trend.The dispersed carbides in high chromium cast iron can effectively improve its wear resistance,and the tempered martensitic matrix provides support for the carbides to prevent them from spalling.The wear property of the sample after quenching at 950 ℃ and tempering at 250℃is the best,which is 41.4%higher than that of the sample after quenching at 1000℃and tempering at 250℃.
作者
李毅
赵继云
朱鹏霄
LI Yi;ZHAO Ji-yun;ZHU Peng-xiao(School of Mechatronic Engineering,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China;Jiangsu XCMG Engineering Machinery Research Institute Co.,Ltd.,Xuzhou 221004,Jiangsu,China;School of Chemical Engineering&Technology,China University of Mining and Technology,Xuzhou 221l16,Jiangsu,China)
出处
《铸造》
CAS
北大核心
2023年第10期1284-1287,共4页
Foundry
关键词
Cr23高铬铸铁
显微组织
碳化物
冲击韧性
抗磨性
Cr23 high chromium cast iron
microstructure
carbide
impact-toughness
wear resistance
