电子束重熔对铁基粉末冶金表面耐磨性能的影响

Effect of Electron Beam Remelting on the Wear Resistance of Iron-based Powder Metallurgy Surface

通过电子束对铁基粉末冶金制品的表面进行重熔处理,以达到提高表面硬度和耐磨性的目的。结果表明:经过电子束重熔处理后,铁基粉末冶金制品表面组织发生了转变,逐步从奥氏体+珠光体转变为针状马氏体+残余奥氏体。当电流为8 mA时,因为组织未能完全熔化,所以仍会有较多奥氏体存在;当电流增大至9 mA时,组织将完全转变为马氏体和残余奥氏体,且随着电流的继续增大,组织中残余奥氏体的含量也逐渐降低。电子束重熔处理能有效地降低铁基粉末冶金制品表面的孔隙率,并促使组织发生马氏体转变,从而提高表面耐磨性能、降低磨损率。同时,随着电流的增大,样品表面耐磨性能逐渐提升。

The surface of the iron-based powder metallurgy sample is remelted by electron beam in order to improve its hardness and wear resistance. Results show that the structure of the iron-based powder metallurgy sample has gradually transformed under the remelting treatment by electron beam, from austenite + pearlite to acicular martensite + residual austenite. With the current 8 mA, there still exists a amount of austenite since the structure has not been completely melted. When the current increases to 9 mA, the structure has completely transformed to martensite and residual austenite. As the current continues to increase, the content of residual austenite in the structure gradually decreases. The electron beam remelting treatment can effectively reduce the porosity of iron-based powder metallurgy samples and promote the martensite transformation, thereby improving the surface wear resistance and reducing the wear rate, and the wear resistance of the sample surface gradually improves with the increase of the current.