模具钢表面盐浴渗钛层的制备及性能研究

采用盐浴法在Cr12Mo V冷作模具钢表面进行渗钛处理,研究了不同温度和时间对渗层厚度的影响。通过金相显微镜、扫描电镜、X射线衍射仪、显微硬度测试仪和旋转摩擦试验仪分析了渗层的显微形貌、相结构、表断面硬度和耐磨性能。结果表明:通过配方优选,在适宜的渗入温度(1000℃)和时间(6h)下,可在模具钢表面形成致密、厚度约13μm的渗钛层,相组成主要为Ti C,渗层具有较高的表面硬度(约2789HV0.3)。室温干摩擦试验表明,与基体相比,相渗层试样的磨损量降低约17倍,平均摩擦系数为0.4054,仅为基体的70.6%,说明模具钢盐浴渗钛处理后具有较佳的耐磨减摩性能。

Microstructure and Properties of Titanizing Layer on Die Steels by Salt Bath Metal Cementation

Salt bath titanizing was performed on Cr1 2MoV steel substrate.The influences of process temperature,and time on the thickness of the layer were studied.The coatings were characterized in terms of microstructure,roughness and surface mechanical properties by optical microscope (OM),scanning electron microscope (SEM),X-ray diffraction (XRD),micro-hardness tester,multifunctional surface properties tester.The results indicated that the dense titanizing coat-ing with the thickness was about 1 3μm at 1 000℃for 6h.The coating mainly consisted of TiC and the value of micro-hard-ness is about 2789HV0.3 .The wear behavior of the coating was investigated.The results showed that the worn loss of the coated sample was 1 7 times smaller than the steel substrate.The average friction coefficient of the titanizing coating was about 0.4054 and it was only 70.6% of the substrate,indicating better wear resistance after titannizing of die steels.