超级贝氏体钢的现状和进展

超级贝氏体钢的基本合金元素为C-Mn-Si,通过300～500℃低温相变得到超细贝氏体、马氏体和残余奥氏体组织。为减小临界冷却速度、促进贝氏体转变,部分超级贝氏体钢中添加Cr、Ni、Mo等合金元素,并降低C、Mn含量以改善钢材的焊接性能。超级贝氏体钢具有超高强度和良好的塑性,其屈服和抗拉强度分别达～1 200MPa和1 600～1 700 MPa,总伸长率为～15%。新一代超级贝氏体钢的屈服强度可达1 300 MPa以上,抗拉强度超过1 700 MPa。

Status and Progress of Super-Bainitic Steels

The basic alloying elements in super-bainitic steels are C-Mn-Si and the structure of ultra-fine bainite, martensite and residual austenite is obtained by low temperature phase transformation at 300～500℃.In order to decrease critical cooling velocity,promote bainite transformation,partial super-bainitic steels are added Cr,Ni,Mo etc.alloy elements with decreasing C,Mn content to improve weldability of steel products.The super-bainitic steel has ultra-high strength and better plasticity,and its yield and tensile strength are respectively～1 200 MPa and 1 600～1 700 MPa with elongation～15%.The yield strength of new generation super-bainitic steel is more than 1 300 MPa,and its tensile strength is more than 1 700 MPa.