机构地区: 广州工程技术职业学院
出 处: 《热加工工艺》 2009年第14期140-143,共4页
摘 要: 对20钢试样离子渗氮后在900℃以下进行盐浴渗铬,分析了渗铬层的形成过程、成分、组织和相结构,并对20钢试样离子渗氮以及渗氮后渗铬进行了硬度对比分析。结果表明,渗氮后进行渗铬能有效提高钢件的表面硬度。低温复合渗铬的保温温度的提高能够提高渗铬扩散速度,以获得更大的渗铬层厚度,且在保温6 h的条件下获得了最佳渗铬层组织。 The heat treatment process of plasma-nitriding at 540 -600℃ followed by a low-temperature chromizing in a salt-bath below 900 ℃ for the steel 20 was put forward. The forming process, ingredient, microstructure and properties was analyzed. The surface microhardness of steel 20 specimens was contrasted between the technics of the plasma-nitriding and low-temperature compound chromizing. The results show that, the hardness of the steel can be improved under the process ofplasma-nitriding and followed by a low-temperature chromizing. Moreover, the speed of chromizing diffusion and the thickness of the compound chromized layer increases if the higher chromized holding time is used, and the optimum microstructure of the compound chromized layer can be obtained if six hours holding time is used.