热处理的冷却过程与零件质量、产品成本和劳动条件有密切关系。正确选择冷却介质,零件可以减少变形、防止开裂、保证达到所要求的组织和性能,还能改进工艺、提高生产率、节约能源、降低成本、消除污染和改善劳动条件。应用相同的介质,如果改进冷却方法和适当调整工艺参数,可获得更佳的热处理效果。 1.国外概况最常用的水、油两种介质,各有其优缺点,这是众所周知的。油因在珠光体转变区冷速慢,淬火烈度低,受热易氧化、裂解,产生老化,影响淬火件表面的色泽或出现软点,甚至淬不硬。国外研究在油中加入钠、钡等磺酸盐,碱金属磷酸盐或生产合成油脂酸的副产品等,再配合搅拌、喷淋、超声强化和改进淬火设备的设计等都可以提高冷速。油经不同方法净化处理,如真空蒸馏、脱气,去除水分、氧、硫、树脂和残碳等夹杂物,另加双 Heat treatment of the cooling process and parts quality, product cost and working conditions are closely related. Correct choice of cooling medium, parts can reduce deformation, prevent cracking, to ensure that the required organization and performance, but also improve the process, improve productivity, save energy, reduce costs, eliminate pollution and improve working conditions. Use the same medium, if you improve the cooling method and adjust the process parameters, you can get better heat treatment effect. 1. Foreign Overview The most commonly used water, oil two media, each with its advantages and disadvantages, it is well known. Oil due to slow cooling zone in the pearlite transformation zone, low quenching intensity, easy to oxidation by heat, cracking, aging, affecting the quenching surface color or soft point, or even hardened. Foreign research in the oil by adding sodium, barium and other sulfonates, alkali metal phosphate or the production of synthetic fatty acid by-products, etc., together with mixing, spraying, ultrasonic strengthening and improving the design of quenching equipment and so can increase the cooling rate. Oil purification by different methods, such as vacuum distillation, degassing, removal of moisture, oxygen, sulfur, resin and residual inclusions, etc., plus double