高频真空电磁感应脉冲渗碳装置及其应用

High-frequency vacuum electromagnetic induction pulse carburizing and its application

针对常规真空电阻式加热渗碳装置加热速度慢、工艺周期长等问题,提出高频真空电磁感应脉冲渗碳方法,自主研制基于PLC控制的电磁感应真空脉冲渗碳装置。其具有升温快、工艺周期短、实现在线监测压力和温度;实现自动混合不同比例的渗碳气氛和整个电磁感应真空脉冲渗碳过程自动化等优势。可完成不同"强渗-扩散"时间占比以及压强、温度随时间在-80~0 k Pa、300~1300℃范围内变化的脉冲渗碳工艺。通过使用该装置对20CrMnTi钢进行8个不同"强渗-扩散"时间占比的脉冲渗碳工艺,制备材料表面含有Fe3C、Fe等碳化物相的渗碳层,碳化物层的硬度达到835.2 HV0.025,渗碳层深度达到1398μm,优于常规真空电阻渗碳方法。

Aiming at the problems of slow heating rate and long process period of the conventional vacuum resistance heating carburizing equipment,a high-frequency electromagnetic induction vacuum pulse carburizing method was proposed,and an electromagnetic induction vacuum pulse carburizing equipment based on PLC control was independently developed.It has a fast heating rate,short process cycle,online monitoring of pressure and temperature,automatic mixing of different proportions of carburizing atmosphere and program control of the entire process of electromagnetic induction vacuum pulse carburizing.It can complete different"strong seepage-diffusion"time ratios and can change pressure and temperature respectively with time in the range of-80-0 k Pa and 300-1300℃.By using the equipment,a pulse carburizing process with 8 different"strong seepage-diffusion"time ratios was carried out on 20 CrMnTi steel,and a carburized layer containing Fe3 C,Fe and other carbide phases was prepared on the surface of the steel,the highest hardness and the thickness of the carbonized layer reach 835.2 HV0.025 and 1398μm respectively,which are superior to that obtained by the conventional vacuum resistance carburizing method.