一、国内外热浸镀情况及意义缩短可锻铸铁石墨化退火时间,以降低成本提高生产效率,这是可锻铸铁生产中极为重要的一个研究课题。长期来,人们经过不断研究试验,采取了很多生产上行之有效的方法,诸如低温处理、高温处理、淬火应力、新孕育剂和孕育方法等等。但是直到目前,据很多快速退火的研究报告,就是在实验室的易控条件上,最快的石墨化速度第一阶段也仍需要2～4小时,第二阶段需4～6小时,生产条件下则更是长达数十小时。这是关系到可锻铸铁在目前各种高强度铸铁材料中能否进一步发展的生命悠关的大问题。近年来,国外在不同介质中进行退火,加速石墨化作了不少研究。这些介质诸如气体的一氧化碳(CO),二氧化碳(CO_2)氩气(Ar)等:液体介质的各种盐浴,如氯化钡75％+氯化钠25％以及铝的热浸镀等。据国外专利的简略介绍,在铝液浸镀过程中,使渗碳体分解的时间为数十分钟,完成可锻铸铁件的一阶段石墨化及热浸镀的全部过程仅需 First, the domestic and international hot dip coating situation and significance Shorten the malleable iron graphitization annealing time, in order to reduce costs and increase production efficiency, which is a very important research topic in the production of malleable iron. For a long time, people have been continuously researching and testing, and many effective methods of production have been adopted, such as low temperature treatment, high temperature treatment, quenching stress, new inoculant and inoculation method and so on. However, up to now, according to many research reports on rapid annealing, that is, in the lab’s easy-to-control conditions, the fastest graphitization speed still takes 2 to 4 hours in the first stage and 4 to 6 hours in the second stage, and the production conditions Under the more is up to dozens of hours. This is related to the malleable iron in the current various high-strength cast iron materials can further develop the life of the big problem. In recent years, foreign countries in different media annealing, accelerated graphitization made a lot of research. Such media as gas carbon monoxide (CO), carbon dioxide (CO2) argon (Ar) and the like: Various salt baths for liquid media such as 75% barium chloride + 25% sodium chloride and hot dip coating of aluminum. According to a brief introduction of foreign patents, in the aluminum liquid immersion plating process, the time for cementite decomposition is several ten minutes, and the first step of complete malleable iron casting and hot dip coating process