屈服强度800MPa的低碳微合金钢

Microalloying Steels with 800 MPa Yield Strength

研究了不同成分特征的含锰低碳微合金钢通过往轧控冷后回火的组织与力学性能．Ｍｎ含量为１．７％～２．３％的试验钢轧后经快冷和中温回火获得了高强度和一定的塑性、韧性．其中含０．０６％Ｃ，２．３％Ｍｎ，０．２１％Ａｌ和微量Ｎｂ，Ｔｉ，Ｂ的快冷回火钢屈服强度（０．２）超过８００ＭＰａ，延伸率大于 １４％，室温冲击韧性１３４～１７４．５ Ｊ／ｃｍ２，－４０℃冲击韧性为 １０３—１１０Ｊ／Ｃｍ，具有由变形奥氏体转变成的细小贝氏体组织．

Mecbanical Properties and microstructure of low carbon manganese clean steels microalloyed with Nb, Ti, B were studied. High levels of yield strength (>800 MPa ) have been attained in the tempered steel containing 0.06%C,2.3%Mn, 0.21%Al and small amount of Nb, Ti, V, B. The elongation elongation of this steel is more than 14% and V-notch toughness is 134~174.5 J/Cm2 and 103~110J/cm2 at room temperature and -40 respectively. Very for bainitic structure (with lath width in micrometer or less) was observed in the steel. Effects of deformation as well as Al additive on the austenite-bainite transformation and mechanical properties have been investigated.