【摘要】 本文研究了微合金化12SiMoVNb 钢经不同工艺处理后得到的粒状贝氏体显微组织与力学性能的关系。结果表明,显微组织参数的变化对准静态力学性能σ_0.2,σ_b,δ,ψ影响不大,而对动态力学性能α_k 影响较为显著。微合金化的粒状贝氏体组织有高的缺口敏感性。在冷却过程中形成细小碳化物沉淀降低基体塑性变形能力,是致脆因素之一。加快冷却速度,形成较细小的,富奥氏体的（M-A）小岛将改善冲击韧性。更多还原

【Abstract】 The relationship of microstructure and mechanical properties of a micro-alloyed 12SiMoVNbsteel with granular bainite structure has been studied.It was found that changes in microstructuredid not appreciably affect the quasi stati(?) mechanical properties but did affect the dynamicproperties,such as impact toughness,considerably.It is believed that the micro-alloyed steelwith granular bainite structure are highly notch sensitive.Extremely fine precipitates of carbidesformed in the course of cooling reduce the plastic deformability of the matrix,therefore play anembrittling role.Increasing cooling rate which causes M-A islands finer and more rich in retainedaustenite,can improve the impact toughness.更多还原