Ti对铬钼钒模具钢奥氏体化组织与性能的影响

??The microstructure and properties of die steels with Ti and without Ti at different austenitizing temperatures were studied through the combination of thermodynamic calculation and experiment. The results show that the total solution temperature of Cr23C6, Cr7C3, VC, V2C, V8C7, MoC, Mo2C and TiC is 748. 2, 952. 7, 977. 3, 632. 9, 1116. 0, 1131. 2, 645. 3 and 1044. 1??, respectively. Hardness and impact toughness both increase with the increase in temperature. When the austenitizing temperature is above 1200 ??, it has a greater influence on the hardness. Toughness of die steel with Ti is better than that without Ti. The grain becomes coarse and the amount of martensite increases with the increase of temperature. The average grain size of the die steel with Ti is 21. 4??m smaller than that without Ti, and the size of the undissolved phase of the former is about 0. 2??m smaller than that of the latter.     

回转窑多相传输过程数值模拟研究进展

回转窑是冶金过程重要热工设备,研究窑内传输过程对优化窑体设计,提高生产效率具有重要意义。文章综述国内外回转窑传输模型的研究现状,介绍多种建立回转窑传热传质模型方法,对每种模型优缺点进行论述。研究表明,模型可以对窑内温度分布等热工参数进行预估,但存在研究窑内燃烧过程时没有考虑气体辐射变化率、简化窑内模型等问题。     

Ti对铬钼钒模具钢奥氏体化组织与性能的影响

采用热力学计算与试验结合的方法研究了含Ti模具钢和不含Ti模具钢在不同奥氏体化温度下的组织与性能。研究表明,Cr_(23)C_6、Cr_7C_3、VC、V_2C、V_8C_7、MoC、Mo_2C、TiC的全固溶温度分别为748.2、952.7、977.3、632.9、1 116.0、1 131.2、645.3和1 044.1℃。随温度升高硬度及冲击韧性增大,奥氏体化温度高于1 200℃时,其对硬度影响更大,含Ti模具钢韧性优于不含Ti模具钢;随温度升高晶粒由细变粗,马氏体增多;含Ti模具钢平均晶粒尺寸比不含Ti模具钢平均晶粒尺寸小21.4μm;含Ti模具钢中未溶相尺寸比不含Ti模具钢未溶相尺寸小0.2μm左右。