层错能对Fe-Mn-C系TRIP/TWIP钢变形机制影响  

Influence of stacking fault energy on deformation mechanism of Fe-Mn-CTRIP/TWIP steels

作　　者：曾敬山[1] 熊杰[1] 史文[1] 李麟[1] 

机构地区：[1]上海大学材料科学与工程学院,上海200072

出　　处：《材料科学与工艺》2013年第2期72-76,共5页Materials Science and Technology

基　　金：国家重点基础研究发展规划(973)资助项目(2010CB630802)

摘　　要：对三种不同层错能(SFE)Fe-Mn-C系TWIP钢的变形机制进行了研究.结果表明:在淬火态下,TWIP钢组织为全奥氏体,奥氏体晶粒内存在少量退火孪晶.TWIP钢的层错能随着C、Mn含量的增加而增加.层错能为7 mJ/m2时,变形后出现大量ε马氏体,且随着应变量的增大,ε马氏体峰增强,表现为单一的TRIP效应;层错能为12 mJ/m2时,应变诱导γ→ε→α或γ→α的转变及形成少量形变孪晶,表现为TRIP/TWIP效应;层错能为18 mJ/m2时,变形后形成大量形变孪晶,表现为单一的TWIP效应,抗拉强度和延伸率分别达到851 MPa及49%.随着层错能增加,TWIP钢的断裂机制由沿晶断裂转变为以韧窝为主的塑性断裂.The deformation mechanisms of three TWIP steels with different stacking fault energy in Fe-Mn-C system were discussed in this paper.Results show that the microstructure is fully austenitic in quenching state and a few annealing twins in matrix of these steels.With the increasing of content of C and Mn,the stacking faulty energy of TWIP steel increases.When SFE is equal to 7 mJ/m2,there are a mass of ε-matensite in TWIP steel after deformation and the volume of ε-martensite enhanced with the increasing of strain,which shows the dominant TRIP effect.When SFE is equal to 12 mJ/m2,strain induces γ→ε→α or γ→α phase transformation and a few mechanical twins,which shows the TRIP and TWIP effects.When SFE is equal to 18 mJ/m2,a large amount of mechanical twins forms after deformation,which expresses single TWIP effect,resulting in a higher tensile strength（up to 851 MPa） and elongation（49%）.With the increasing of SFE,the fracture mechanism of three TWIP steels turns to ductile fracture with dimples from brittle fracture.

关 键 词：TWIP钢 Fe-Mn-C 层错能(SFE) 变形机制 

分 类 号：TG142.25[一般工业技术—材料科学与工程]