Abstract Micro-alloyed steels is a high technology in the fields of materials and metallurgical engineering,adding trace metal elements Nb,V, Ti etc。 into steel, improve the strength and toughness of steel,which can put in a low cost of the steel's overall performance has improved significantly。 Today,about mechanical properties of micro-alloyed steel casting molds there has been a lot of research,but on different Ni, Mo,Si and Mn content of micro-alloyed of fewer studies on mechanical properties of micro-alloyed steel casting molds,there is necessary to study the mechanical properties of micro-alloyed steel casting molds 。
In this paper,the effects of different Ni,Mo,Si and Mn contents on the mechanical properties of die steel are studied,which are pided into 3 kinds of steel,407steel, Dievar steel and U2 steel。 The hardness,tensile and impact properties of die steels with different Ni,Mo,Mn and Si were compared and studied,the influence of Ni and other elements on the mechanical properties of die steel is discussed。
Research results show that: (1) the hardness of three types of steel from large to small: Dievar steel,U2 steel,407steel;(2) Tensile strength from high to low is: U2 steel, steel Dievar, 407steel。 Yield strength from high to low: U2 steel, steel Dievar, 407 steel。 Plastic of from high to low: steel Dievar, 407 steel, U2 steel; (3) Toughness from good to bad for: steel Dievar, 407 steel, U2 steel 。
Key words:Micro-alloyed;die Steel;hardness; tensile properties;impact performance