高温模具表面激光熔覆耐磨合金

Laser Cladding of Alloy Coating for wear Resistance on the Surface of High Temperature Tool

用2kw CO 激光和送粉工艺,在4Cr5MoV_1Si 钢表面熔覆一层高温耐磨合金(Ni 基高温合金+WC),并应用于轧钢机导向板工作面。用扫描电子显微镜、电子探针和 x 射线衍射技术分别进行熔覆层的组织形态观察,微区成分分析和物相的鉴定。结果表明,熔覆层显微组织主要有许多弥散分布的 W_2C、(W,Ti)C_(1-x)、WC 和共晶态的 M_(12)C 及γ(f、c、c)母体相组成。室温及高温硬度测试结果表明,熔覆层有适中的室温硬度和相对较高的高温硬度。实际生产考核结果表明,激光熔覆导向板使用寿命大大提高,每对可轧钢1000～1100吨,而4Cr_5MoV_1Si 和普碳钢分别为400～500吨和200吨。

A 2KW CO_2 laser and a powder feeder are used for the laser cladding of wear resisting alloy at high temperature,being prepared for the working surface of the directing plate of rolling mill.A scanning electron microscope equipped with an ene- rgy dispersive X-ray microanalysis system is employed for the studies of microstruct- ure evaluation and microchemical analysis.X-ray diffraction technique has been used to characterize the phases formed buring cladding process.The results show that the microstructure of cladding layer mainly consistes of many dispersed fine particles. Hardndss of room temperature and high temperature shows that cladding zone has a moderate room temperature hardness and relatively hrgher high temperature hardness. The result of real rolling in the mill of the loser-clad directing plate reveals that its lifetime is longer than that of 40rSMoVlSi steel and plain steel.