The Forging Ratio H13 Steel Microstructure And Mechanical Properties

H13 steel is one type of hot die steel that used very widespread in the world nowadays, which adopted in producing region of the hot-working model and copper-alloy, aluminum-alloy casting model, by the good heat resistance, ductility and hardenability. H13 steel is divided mainly to electric furnace steel according to casting method and electro-flux refining furnace steel which better than electric one in property. The die steel that made by traditional electric furnace casting method is still used widely because of its lower cost than electro-flux refining one, adopting electric furnace steel as base metal especially for low and medium-grade hot die assembly working in 500 to 600 degree Centigrade. It will bring higher economic performance, if we use more reasonable heat processing or forging methods which would increase the quality, performance and service life of the electric furnace steel-assembly.Being processed by simplex hot forging or hot rolling is always widely adopted to electric furnace-bar steel in factory, but the systematically research of the forging ratio is not enough, and related literatures are few too. In this paper, electric furnace die H13steel is studied using facilities including metallographic microscope, SEM, energy spectrum analysis, impact test and tensile test under simplex, doing research to the influence of different forging ratios on the structure and mechanical property, representing systematically the factors of the effect to the test steel performance and the structure characters of electric furnace steel, discussing the effects and their mechanical properties of the transversal and longitudinal of the steel processed by simplex hot forging and stretching, advising the best forging ratio. This paper is of current significance to producing electric furnace H13 steel, and ground the therapies for developing economic advantage.This research base on the supporting by Center of Dongbei special steel group with the raw material H13 steel casted by electric furnace. There're mainly conclusion as below after experience and analysis:1.The rather large difference between electric and electro-flux refining furnace of the performance, caused by the electric worse than the electro-flux refining on structural homogeneity. The less properties of electric furnace steel bar is the reason why the lower performance of the product.2. The influences to mechanical performance of the transversal and longitudinal of the steel are different, because the specialist of simplex hot forging and stretching which changes its shape from one direction. The breaking direction of the transversal is nearly consistent to intensive carbides existence as continuous chain, as a result, the steel's property depends on carbide's number. On the other hand, the mechanical properties of the longitudinal of the steel are decided by the degree of homogeneity of the banding segregation.3.Increasing forging ratio will bring rather little positive effect to the mechanical properties of the transversal of the steel, especially to the compact ductility, for electric furnace casting H13 steel forged from simplex direction.4. The increasing of the compact ductility and tensile property of the longitudinal of the steel is along with the increasing of forging ratio. Larger than four of the forging ratio, continual increasing ratio will not only lower the increasing trend of the compact property on the longitudinal direction of the steel, but the improvement to tensile property is rather little. Confining the forging ratio in four to six is the best choice for the steel in this experiment.