Research on the Microstructure and Wear Resistance of Hardfacing Layer on Big Cold Trimming Die Insert

摘要

It's a simple technology to manufacture big trimming die by hardfacing on the die insert of cast iron. Here, the chemical composition, microstructure, micro-hardness, wear resistance and wear mechanism of the hardfacing layer with a newly developed electrode have been studied. The experimental results indicate that the hardfacing technology has much more advantages and cheaper than that of traditional process. The chemical composition, microstructure, micro-hardness of the hardfacing metal are all satisfied for manufacturing the big trimming die by welding on die insert of cast iron. The wear resistant test of hardfacing layers were carried out by using M2000 type tester with two different electrodes. The wear resistance of new electrode hardfacing layer is higher than that of normal hardfacing electrode D322. The wear mechanism of hardfacing layer belongs to abrasive wear model. The service life of hardfacing die insert is as long as tool steel insert which was fully heat-treated. More than 25000 workpieces can be carried out by using the hardfacing die insert. The life of repaired cold die with new kind of hardfacing electrode bar can be raised up to 30～50% than that with the electrode D322 under the same condition.