Fe-27Mn-11Al-0.9C低密度钢变形开裂机理研究  

Study on deformation and cracking mechanism of Fe-27Mn-11Al-0.9C low density steel

作　　者：李振江 庞有超 赵永琦 胡旭涛 齐会萍[1] 杨雯[1] LI Zhen-jiang;PANG You-chao;ZHAO Yong-qi;HU Xu-tao;QI Hui-ping;YANG Wen(Shanxi Key Laboratory of Metal Forming Theory and Technology,School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学材料科学与工程学院金属材料成型理论与技术山西省重点实验室,山西太原030024

出　　处：《塑性工程学报》2024年第12期229-236,共8页Journal of Plasticity Engineering

基　　金：山西省重点研发计划项目(202202150401007);山西省基础研究计划项目(202203021211207);山西省科技创新人才团队专项(202204051001002)。

摘　　要：通过Gleeble-3500热模拟实验机对Fe-27Mn-11Al-0.9C低密度钢进行不同温度(700~1200℃)的等温拉伸实验,研究了不同温度下实验钢的变形行为并观察了断裂后的微观组织。结果表明:在700~1200℃温度下进行等温拉伸实验,基体组织为奥氏体和铁素体两相,流变应力随着温度的升高而逐渐降低,700℃等温拉伸塑性最差,800℃等温拉伸塑性居中,900~1200℃等温拉伸时塑性都较好。变形温度不同,组织会有差别,进而导致拉伸断裂机制不同。700℃等温拉伸时,在奥氏体晶界处有κ-碳化物生成,断裂形式为典型的沿晶断裂。800℃等温拉伸时,晶界仍然有脆性的κ-碳化物析出,但该温度下变形时奥氏体能够发生塑性变形,导致800℃拉伸断裂为沿晶延性断裂。当拉伸温度为900~1200℃时,碳化物未析出,塑性显著增强,在奥氏体和铁素体的相界处发生断裂,为韧性断裂。The isothermal tensile experiments of Fe-27Mn-11Al-0.9C low density steels were conducted by Gleeeble-3500 hot simulator at different temperatures(700-1200℃).The deformation behaviors of the experimental steel at different temperatures were studied and the microstructure after fracture was observed.The results show that during isothermal tensile experiments at 700-1200℃,the microstructure of the matrix is austenite and ferrite,the flow stress decreases gradually with the increase of temperature.The plasticity is the worst after isothermal tensile at 700℃,slightly better after isothermal tensile at 800℃,and good after isothermal tensile at 900-1200℃.Different deformation temperatures result in different microstructure,which in turn result in different tensile fracture mechanisms.When the isother-mal tensile temperature is 700℃,theκ-carbide is formed at the austenite grain boundary,and the fracture mode is typical intergranular fracture.When isothermal tensile temperature is 800℃,brittleκ-carbide still precipitates at the grain boundaries,but austenite is de-formed plastically,leading to ductile intergranular fracture at 800℃.When the tensile temperature is 900-1200℃,there is no carbide precipitation,the plasticity is significantly enhanced,and the fracture occurs at the phase boundary of austenite and ferrite,which is duc-tile fracture.

关 键 词：Fe-27Mn-11Al-0.9C 等温拉伸 微观组织 κ-碳化物 断裂机制 

分 类 号：TG142.1[一般工业技术—材料科学与工程]