高强度低合金调质钢两相区超塑性机理研究  

Mechanism of Superplasticity of High-strength Low-alloy Quenched and Tempered Steel in the Two-phase Region

作　　者：薛钢[1] 杨超飞[1] 邓晚平[1] 王任甫[1] 

机构地区：[1]中国船舶重工集团公司第七二五研究所,河南洛阳471023

出　　处：《材料开发与应用》2015年第1期8-14,共7页Development and Application of Materials

摘　　要：研究了10CrNi3MoV钢超塑性温度拉伸应力应变特征,分析了不同程度变形钢的微观组织和断裂行为,用塑性应变分布场数值模拟研究了高强度低合金调质钢两相区超塑性机理。研究结果表明,低屈服应力的奥氏体相围绕高屈服应力的铁素体相呈网状联通分布,通过自身的塑性变形起到"润滑油"作用;经过一定程度的变形后,强烈的应变硬化使奥氏体相的应力超过铁素体相的屈服应力,促进铁素体相的塑性变形;高应变区的铁素体相转变生成奥氏体相,为后续变形补充"润滑油";持续的"塑变-相变"行为维持大变形中的整体连续性,材料表现为超塑性。Mechanism of superplasticity of high-strength low-alloy quenched and tempered steel in the two-phase region is proposed through analysis of tensile stress-strain characteristics of the 10CrNi3MoV steel at superplastic temperature. Microstructure and fracture behavior of different degrees of deformation and numerical simulation of the distribution of plastic strain fields were analyzed. Results showed that the austenite phase with low yield stress around the ferrite phase with high yield stress is unicom,and it acts as a ＂ lubricant＂ role through its own plastic deformation. After a certain degree of deformation,stress of the austenite phase exceeds the yield stress of ferrite phase because of strong strain hardening,which promotes the plastic deformation of the ferrite phase. Ferrite phase in high strain zones transforms into austenite grain,which supplies lubricant for the subsequent deformation. Continuous plastic deformation- phase transition maintains the large deformation behavior overall and continuity,material shows superplasticity.

关 键 词：调质钢 两相区 超塑性 相变 

分 类 号：TG142.1[一般工业技术—材料科学与工程]