摘要
在熔炼过程中对成分为1号:3.2C-1.0Si-0.6Mn-1.5Cr-2.0Ni;2号:3.2C-1.0Si-0.6Mn-1.5Cr-4.0Ni-0.7Mo的铸铁进行复合变质处理,制备变质铸铁试样。对试样进行球化退火、淬火及回火处理。观察试样各种状态的微观组织,测定其宏观硬度和抗拉力学性能。结果表明:变质处理能显著破坏碳化物网状结构,得到彼此孤立的块状碳化物。在950℃淬火后变质试样,分别在300℃、430℃、630℃回火,结果显示,随着回火温度的升高,马氏体完全分解的数量增多,硬度逐步下降。球化处理后,组织中出现了大量球粒状珠光体和渗碳体,硬度下降;两种铸铁抗拉强度分别为880 MPa和1 050 MPa,伸长率为2.8%、2.4%。
The modified cast iron specimens were prepared by bringing the multi-modification into the melt during melt-casting process.Alloy 1：3.2C-1.0Si-0.6Mn-1.5Cr-2.0Ni;Alloy 2：3.2C-1.0Si-0.6Mn-1.5Cr-4.0Ni-0.7Mo.The specimens are annealed.The optical images shows that the lattice structure of carbides were broken and the carbides became isolated after modification.The specimens were quenched at 950 ℃,then tempered alternatively at 300 ℃,430 ℃,630 ℃,the optical images shows that the martensite decreased and the hardness decreased with the increase of temperature.A spheroidizing technology was applied to the specimens.There is some spherical pearlite and cementites appeared,and the hardness is lower than the tempered specimens.The tensile strength of the modified cast iron 1 and 2 are 880 MPa and 1 050 MPa respectively,while the elongation is poor,2.8% and 2.4%.The probable reason is that the temperature of spheroidizing anneal is low that there are still unspherical cementites.
出处
《湖南有色金属》
CAS
2010年第6期34-38,共5页
Hunan Nonferrous Metals
关键词
白口铸铁
变质处理
淬火回火
球化退火
white cast iron
modification
tempering
spheroidization anneal
