凹凸棒土基高温防脱碳涂层的研究

摘要

To reduce oxidation decarburization of steel during heat treatment, anti-decarburization coating was prepared with attapulgite as main starting material,adding a certain amount of AI2O3,SiC,and Cr2O3 powders,and mixing in potassium silicate aqueous solution. The coating was painted on the surfaces of steel 60Si2Mn and steel GCrl5 and dried at 60 °C for 2 h. High temperature decarburization resistance test was conducted by heating the steel at 850-1 150 °C for 30-120 min. The performance and mechanism of decarburization resistance at high temperatures of the coating was investigated through optical microscopy and XRD. The results show that the coating can reduce the thickness of decarburization layer of the two types of steel obviously;as the temperature increases and soaking time prolongs,the coating performs well;the coating protects the steel by forming a dense layer and the oxidation of SiC in the coating.%为了避免钢在热处理过程中表面发生氧化脱碳,以凹凸棒土(ATP)为主要原料,加入一定比例的Al2 O3、SiC和Cr2O3等粉末和硅酸钾水溶液配制成涂料,刷涂于60Si2Mn和GCr15两种钢材表面并在60℃下烘干2h形成涂层,然后对此涂层进行热处理温度850～1 150℃、保温时间30～120 min的高温防脱碳试验,并采用光学显微镜和X射线衍射仪等对涂层的保护效果和保护机制进行了研究.结果表明:该涂层能够显著降低这两种钢材的脱碳层厚度,并且随着保温时间的延长和加热温度的升高,涂层防脱碳性能仍然保持良好；该涂层通过形成致密覆盖层以及涂层中SiC的氧化反应而对钢材起到防脱碳作用.