Studies On The Quality Of 4Cr5MoSiV Steel Forging Die Made By Squeeze Casting

Liquid forging is a new metal-forming technology. If forging die can be manufactured with this technology , the useless forging die can be remelted, thus a good deal of the die steel will be reclaimed. In addition, the forging die mold groove will be more accurate than that produced by forging , and the machining process is also reduced, the manufacture process will be shortened, the technology is feasible and it is promising in the economy. Based on Dongfeng Motor Company' s practice need, It has great practical and theoretical significance to develop the experimental on squeeze casting for 4Cr5MoSiV steel forging die .It is difficult to acquire high quality forging die. Because the craftwork is difficult, there are many difficulties in controlling the quality of forging die. So it is necessary to analyze and study it.The quality of forging die is studied in this paper, the main contents are as follows, The experiment condition and process are introduced simply. The alloy component is inspected with Spectrum Scanner. The structure of the forging die in different heat treatment is observed and Its mechanical properties is tested. The effect on the structure and mechanical properties in adding the rare earth is studied. The mold groove of the forging die by squeeze casting is compare to that made by forging. The quality of the forging die on the surface and its defects is analyzed in details and several methods are pointed out in decreasing the defects.The quality of the forging die by squeeze casting is investigated. Results show that the alloy component can be controlled in the standard range if the surface of rejected forging die can be cleared up and it is melted in alkalescence furnace. In addition, the ferroalloy should be added proprietily before the melted steel is irrigated. The original structure of the 4Cr5MoSiV steel forging die made by squeeze casting is Martensite, the surface rigidity can reach 52-54HRC. Its rigidity is 210-226 HB after annealed and its rigidity is 52-54HRC after quenched at 1000 C and tempered at 570" C and 560'C . It canbe machined easily after annealed. Fine crystal grain can be acquired and the deflection can be improved by adding rare earth. It has high intension guideline and the ability of distortion is errand and the toughness is low. And its impulsion is low too. The wear-resistant of the mold groove is analyzed. The mold groove is gained under pressure and is cooled quickly. So the product with fine crystal grain and as-casting microstructure is gained by methods of squeeze casting, sequentially the wear-resistant can be improved. The product' s defects include lard , pore, component asymmetry, shrinkage loose and cracks. The lard can be eliminated through choose valid dope and shrinkage loose can be solved after the tonnage of hydraulic pressure machine enhanced. The crack can be avoided in controlling craftwork parameter(time and pressure)and the die is designed in reason.