Influence of V–N Microalloying on the High-Temperature Mechanical Behavior and Net Crack Defect of High Strength Weathering Steel

Abstract The influence of V–N microalloying on the high-temperature mechanical behavior of high strength weathering steel is discussed through thermomechanical simulation experiment. The difference of tensile strength caused by variation of [%V][%N] appears after proeutectoid phase change, and the higher level of [%V][%N] is, the stronger the tensile strength tends to be. The ductility trough apparently becomes deeper and wider with the increase of [%V][%N]. When the level of [%V][%N] reaches to 1.7 × 10 ⁻³ , high strength weathering steel shows almost similar reduction of area to 0.03% Nb-containing steel in the temperature range of 800–900℃, however, the ductility trough at the low-temperature stage is wider than that of Nb-containing steel. Moreover, the net crack defect of bloom is optimized through the stable control of N content in low range under the precondition of high strength weathering steel with sufficient strength.