热处理工艺对高速车轮钢显微组织和断裂韧性的影响

发布时间：2019-03-19 12:56

【摘要】：对含碳量为0.54%的高速车轮钢热处理工艺进行实验研究,得到不同晶粒尺寸和珠光体片间距的显微组织,在室温下对具有不同显微组织的紧凑拉伸(CT)试样进行断裂韧性测试。结果表明,车轮钢的平均晶粒尺寸随奥氏体化温度升高而增加;珠光体片间距随冷却速率增加而减小。车轮钢室温下的断裂模式为解理断裂,断裂韧性主要取决于晶粒尺寸的大小,晶粒尺寸越小,断裂韧性越高。珠光体片间距对断裂韧性有一定影响,粗大的珠光体片间距会降低断裂韧性,并且当晶粒尺寸较小时,珠光体片间距的影响更明显。因此,实际工程中为提高车轮钢断裂韧性,合理的奥氏体化温度是关键,同时需适当增加车轮钢奥氏体化后的冷却速率。
[Abstract]:The heat treatment process of high speed wheel steel with 0.54% carbon content was studied experimentally, and the microstructure of different grain sizes and pearlite slice spacing was obtained. The fracture toughness of compact tensile (CT) specimens with different microstructure was tested at room temperature. The results show that the average grain size of wheel steel increases with the increase of austenitizing temperature and the pearlite spacing decreases with the increase of cooling rate. The fracture mode of wheel steel at room temperature is cleavage fracture. The fracture toughness mainly depends on the grain size. The smaller the grain size is, the higher the fracture toughness is. The spacing of pearlite films has a certain effect on the fracture toughness. The coarse pearlite spacing will reduce the fracture toughness, and when the grain size is small, the effect of pearlite slice spacing is more obvious. Therefore, in order to improve the fracture toughness of wheel steel in practical engineering, a reasonable austenitizing temperature is the key, and the cooling rate of wheel steel after austenitizing should be increased properly at the same time.
【作者单位】：北京科技大学国家材料服役安全科学中心;北京科技大学材料科学与工程学院;马鞍山钢铁股份有限公司技术中心;
【基金】：国家自然科学基金(51171020,U1234207) 中央高校基本科研业务费专项资金(FRF-TP-12-160A)
【分类号】：TG142.1;TG161

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