稀土含量对38CrMoAl钢渗氮层性能的影响

Effect of Rare Earths Content on Nitriding Performance of 38CrMoAl Steel

为了克服38CrMoAl钢渗氮速度慢,渗层脆性大,稀土添加到渗氮气氛中只能作用于工件表面等缺点,研究了38CrMoAl钢中不同稀土添加量对渗氮层性能的影响,并初步分析了其影响机制。研究结果表明:稀土对38CrMoAl钢渗氮具有明显的催渗作用,且能提高渗层性能。原因是稀土加入钢中后,引起周围铁原子的点阵畸变,有利于氮原子的吸附和扩散,且稀土易与渗氮气氛中的氧结合,削弱了氧对渗氮的阻碍作用;同时稀土的晶粒细化、固溶体强化、微合金化也是其改善渗层性能的重要原因。

In order to overcome the shortcomings such as low-speed, long period, thin penetration thickness of ordinary gas nitriding and it just works on the surface of the workpiece if the rare earths was added into nitriding atmosphere, the effect of rare earth addition content on the gas nitriding performance of 38CrMoAl steel was studied. The effect mechanism was also initially analyzed. The results indicate that the rare earth has obvious catalytic effect on the nitriding of 38CrMoAl steel and improves its nirtrding performance. The reason is that the iron crystalline lattice was distorted and the harmful effect of oxygen on the nirding was decreased by the reaction between rare earths when the rare earths was added into 38CrMoAl steel, which fostered the nitrogen atom diffusion. The grain refinement, solution strengthening, micro-alloying are also regarded as the important reasons that the rare earths improve the performance of nitriding layer.