The Study On Compasional Designand Properties Of Cast State Multiphase Steel

This paper has been studied the making-up process of one kind of medium-high carbon alloy steels-the cast austenite-bainite structure steel by the means of optimum of composition, which contains (wt%) 0.45 -0.75%C, 2.0-3.0%Si, 2.0-3.0%Mn, 1.5-2.5%Cr and appropriate content of Mo> V> Ti> Re .The tests were based on the means of the orthogonal tests with L9 (34 ) . During the tests, the smelting temperature was elevated to 1560℃. The pouring temperature was 1500-1520℃. Casting samples were made in green-sand mold. After that, the series of tests including hardness, resistance to shock and abrasion were carried out. The microstructure was inspected and the abrasion was analysed and the optimum content of alloy elements were determined. The influential levels of the alloy elements content, impact toughness and hardness to the relative abrasion resistance were ascertained by the means of the gray connective analysis; furthermore, the influence on theabrasion resistant were predicted by the analysis of the metallographic structure, the carbide , and material properties.The elements added in the tests influence on the hardness are arranged by the orders from major to minor: Cr, Si, C, Mn- especially when their contents are 2.5%,2.5%, 0.60%, 2.0% respectively, hardness reaches the optimum. The elements influence on the impact toughness arranged by the orders from major to minor is C, Si, Cr, Mn-especially when 0.45%, 2.0%, 1.5%, 2.5% respectively, the impact toughness reaches optimum. The elements influence on the relative abrasion resistance arranged by the orders from major to minor is Cr, C, Si, Mn-especially when 2.5%, 0.75%, 2.5%, 2.5% respectively, the abrasion resistance reaches optimum.