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针对中厚板辊式淬火机淬火工艺过程,在分析淬火喷水系统射流流场结构及换热特性的基础上,阐明其淬火过程的热交换机理主要为射流冲击换热。并结合实际工况参数,通过模拟分析不同淬火冷却条件对中厚钢板温度场及应力场的影响规律,指出高压淬火区的高强度冷却是板材内部应力产生的主要因素。研究表明辊式淬火机淬火过程的冷却机理在于:在淬火钢板800～500℃的温度区间,采用高压淬火区高强度冷却,有利于钢板获得大于临界淬火速度的高冷却速率,以避免发生其它类型的组织转变;在500℃以下的温度区间,采用低压淬火区慢冷,有利于减小钢板的热应力和马氏体转变过程中产生的组织应力,从而降低钢板在马氏体转变过程中的综合内应力,减小钢板变形倾向。
Aiming at the quenching process of plate quenching machine, based on the analysis of the jet flow field structure and heat transfer characteristics of quenching water spraying system, the main heat exchange mechanism of quenching process is jet impact heat transfer. The influence of different quenching and cooling conditions on the temperature field and stress field of medium and heavy gauge steel plates was analyzed by simulation. It was pointed out that the high strength cooling of high-pressure quenching zone is the main factor of internal stress generation. The research shows that the cooling mechanism of the quenching process of the roller quenching machine lies in that the high-temperature quenching zone high-strength cooling in the temperature range of 800-500 ℃ of the quenched steel plate is favorable for the steel plate to obtain the high cooling rate greater than the critical quenching speed so as to avoid the occurrence of other types In the temperature range below 500 ℃, the use of low-pressure quenching zone slow cooling, is conducive to reducing the thermal stress and the martensitic transformation of the resulting tissue stress, thereby reducing the plate in the martensitic transformation process Integrated stress, reduce the tendency of plate deformation.