【摘要】 研究了硅对中低碳和中碳ＭｎＢ系空冷贝氏体钢的组织和强韧性的影响。结果表明，硅含量为１４％～１８％时，钢中的贝氏体组织是由残余奥氏体和贝氏体铁素体所组成的无碳化物贝氏体。冷却后的贝氏体／马氏体复相组织具有良好的强韧性。高硅中低碳钢和中碳钢的断裂韧度分别达到１１９ＭＰａ·ｍ１／２和７３ＭＰａ·ｍ１／２，显著高于硅含量低的钢。更多还原

【Abstract】 Effect of silicon content on the microstructure and properties in Mn_B air_cooled bainitic steels has been studied.The results show that the bainite obtainted in steels contained 1 4%～1 8% silicon is carbide_free bainite which consists of bainitic ferrite and retained austenite film exsisting between/in the bainitic ferrite.The microstructure mixed with bainite and martensite in steels with higher silicon content,obtained by continuous cooling,displays appreciably better fracture toughness K 1c than that of steels with lower silicon content.The fracture toughness of medium low carbon and medium carbon steels reaches 119MPa·m 1/2 and 73MPa·m 1/2 respectively.更多还原