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通过对高铬铸铁3Cr14Mn4B的硬度和磁性的测量,研究了高铬铸铁经亚临界处理、去稳处理及深冷处理后的组织和硬度变化,分析了高铬铸铁残余奥氏体和马氏体的相组成对高铬铸铁硬度的影响。结果表明,高铬铸铁的显微组织主要由马氏体、少量的奥氏体和(Cr,Fe)7C3共晶碳化物组成。在亚临界处理的情况下,空冷时高铬铸铁的硬度随亚临界处理温度的增加而先升高后降低,深冷处理后的硬度高于空冷时的,但当温度高于550℃时,深冷处理后的硬度低于空冷时的。高铬铸铁的硬度随去稳处理温度的升高略有升高,并且经深冷处理后的试样硬度比空冷高。经不同的热处理后,高铬铸铁的硬度主要受铸铁基体的马氏体含量和马氏体中的含碳量的影响。最佳的热处理工艺是在550℃进行亚临界处理。
By measuring the hardness and magnetic properties of high chromium cast iron 3Cr14Mn4B, the changes of microstructure and hardness of high chromium cast iron after subcritical treatment, destabilization treatment and cryogenic treatment were studied. The residual austenite and martensite of high chromium cast iron Influence of Phase Composition on Hardness of High Chromium Cast Iron. The results show that the microstructure of high chromium cast iron is mainly composed of martensite, a small amount of austenite and (Cr, Fe) 7C3 eutectic carbides. Under the condition of subcritical treatment, the hardness of high chromium cast iron increases first and then decreases with the increase of subcritical treatment temperature. The hardness after cryogenic treatment is higher than that of air cooling. However, when the temperature is higher than 550 ℃, After cold hardness lower than when air-cooled. The hardness of high chromium cast iron increases slightly with the temperature of destabilizing treatment, and the hardness of the sample after cryogenic treatment is higher than that of air cooling. After different heat treatment, the hardness of high chromium cast iron is mainly affected by the martensite content of the cast iron matrix and the carbon content in the martensite. The best heat treatment process is subcritical treatment at 550 ℃.