高硬度过共晶高铬铸铁的合金化与热处理工艺研究

Study on Alloying and Heat Treatment Process of High Hardness Hypereutectic High Chromium Cast Iron

通过Nb、W、V和B合金化,使过共晶高铬铸铁的铸态硬度得到显著提高。高硬度主要来源于碳、硼化物比例的显著提高和碳、硼化物尺寸的明显细化。大尺寸的碳化物明显消失,微观组织更加均匀,使合金化铸态硬度达到了未合金化样品热处理态的硬度水平。将过共晶高铬铸铁在不同热处理方案下的硬度值进行对比,结果表明,快速冷却相比缓慢冷却会使过共晶高铬铸铁的硬度增加,较低的温度、较长的加热时间以及较长的固溶时间会产生更高的硬度值,炉冷或空冷等回火冷却方式对硬度值影响较小。这为过共晶高铬铸铁提高硬度值、简化热处理流程以及优化生产工艺提供了理论借鉴。

By alloying with Nb,W,V,and B,the as cast hardness of hypereutectic high chromium cast iron is significantly improved.The high hardness mainly comes from the significant increase of the proportion of carbon and Boride and the obvious refinement of the size of carbon and Boride.The large-sized carbides have significantly disappeared,and the microstructure is more uniform,making the hardness of the alloyed cast state reach the hardness level of the unalloyed sample in the heat treated state.Compare the hardness values of hypereutectic high chromium cast iron under different heat treatment schemes.The results indicate that rapid cooling can increase hardness compared to slow cooling,and lower temperatures,longer heating times,and longer solid solution times can produce higher hardness values.Tempering cooling methods such as furnace cooling or air cooling have less impact on hardness values.This provides a theoretical reference for improving the hardness value,simplifying the heat treatment process,and optimizing the production process of hypereutectic high chromium cast iron.