热作模具钢高温销-盘磨损实验研究

Experimental research on high temperature pin-disc wear for hot work die steel

为研究3种常用热作模具钢的高温硬度和在100和300℃温度条件下的磨损率、摩擦因数的变化规律,通过高温硬度实验和高温摩擦磨损实验获得了3种热作模具钢的硬度、摩擦因数、磨损率随温度的变化规律。结果表明:随着温度的升高,硬度逐渐下降,表面渗氮处理虽能够大幅度提高材料硬度,但渗氮处理后的硬度随着温度升高而下降的幅度更明显;300℃下,销-盘接触表面的变形抗力降低,材料与板材之间的摩擦因数小于100℃下的摩擦因数,同时300℃下销表面产生较厚的氧化层,其磨损率小于100℃下的磨损率;材料表面渗氮处理后在100℃下材料的耐磨性提高,但在300℃下磨损量反而增大。实验结果为模具材料的选择和模具耐磨性的提高提供了可靠的基础数据支撑。

In order to study the high temperature hardness of three commonly used hot work die steels and the change laws of wear rate and friction coefficient at 100 and 300 ℃, the laws for the hardness, friction coefficient and wear rate changing with temperature for three types of hot work die steels were obtained by high temperature hardness test and high temperature friction-wear test. The results show that the hardness gradually decreases with the increasing of temperature. Although the surface nitriding treatment greatly increases the hardness of the material, the hardness decreases more obviously with the increasing of temperature after nitriding treatment. At 300 ℃, the resistance to deformation of the pin-disk contact surface is reduced, and the friction coefficient between material and plate is less than that at 100 ℃. At the same time, the pin surface produces a thicker oxide layer at 300 ℃, and the wear rate is less than that at 100 ℃. The surface nitriding treatment of the material improves the wear resistance of the material at 100 ℃, but at 300 ℃, the wear amount increases instead. Thus, the test results provide reliable basic data support for the selection of mold materials and the improvement of mold wear resistance.