The Research Of A Newly Developed Cold Work Cast Die Steel

To produce die steel by casting instead of traditional forging shows some unique advantages. Especially for some complicated designed dies, using the casting method can cast out the specific shape of the dies directly, greatly reducing the subsequent mechanical processing, saving raw materials and cost on the machining process, So using the casting method can reduce the cost and the time for dies production. Another advantage of casting die is the simple subsequent mechanical processing, In contrast to forging die, casting die can use the more difficult-to-machine materials, which often have better comprehensive mechanical properties.The subject of this research is the new casting cold work die steel. In this study, the heat treatment process was optimized, the mechanical properties, the wear resistance and the welding performance was tested.In this study, the cold work die steel was obtained with casting method, the proper alloying elements were added into steel to improve its heat treatment properties and mechanical properties, the reasonable heat treatment process was used to make the cold work die steel with better mechanical properties, including hardness, tensile properties and cutting performance.The wear resistance of cold work die steel under different heat treatment process was studied, with traditional forging die steel Cr12MoV as contrast material, to evaluate the practical application value of the new casting cold work die steel. The wear resistance of the cold work die steel of the optimum heat treatment process was also studied under different working conditions, including different load, different wear velocity and different wear distance. Wear rate and friction coefficient was used to evaluate the wear-resisting performance of the cold work die steel.To check the weldability of the die steel, electrode arc welding method was used to research the welding joint properties of the cold work die steel, including the metallographic structure of the weld and heat affected zone, the hardness regularity of the welded joint, the tensile properties of the welded joint. The weld quality was varied when the current was changed.and the best welding process was determined accordingly.According to the experiment, the new type casting cold work die steel has very good hardenability,1040℃quenching+480℃tempering the best mechanical properties including the best wear resistance performance was obtained. Under the best heat treatment state, the wear-resisting performance of the new cold work die steel is very good, the new cold work die steel can partly replace Cr12MoV application in practical production. The weldability test showed that when the welding current was used on90-110A, the material of the welding joint quality is best.