文献类型：期刊文献

英文题名：Influence of DIMT on impact toughness: Relationship between crack propagation and the a'-martensite morphology in austenitic steel

作者：Huang, Minghao[1];Wang, Chenchong[1];Wang, Lingyu[1];Wang, Jinliang[2];Mogucheva, Anna[3];Xu, Wei[1]

机构：[1]Northeastern Univ, Sch Mat Sci & Engn, State Key Lab Rolling & Automation, Shenyang 110819, Peoples R China;[2]Guangdong Ocean Univ, Sch Mech & Power Engn, Zhanjiang 524000, Peoples R China;[3]Belgorod State Univ, Lab Mech Properties Nanoscale Mat & Superalloys, Belgorod 308015, Russia

年份：2022

卷号：844

外文期刊名：MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

收录：SCI-EXPANDED(收录号：WOS:000797562300001)、、WOS

基金：Acknowledgements The research was financially supported by the National Natural Science Foundation of China (No. U1808208, and 51961130389) , and International/Regional Cooperation and Exchange Program of NSFC (NSFC-RFBR, No. 52011530032) .

语种：英文

外文关键词：a'-martensite morphology; Crack propagation; Grain size; Austenitic steel; Deformation-induced martensitic; transformation

外文摘要：The trade-off between transformation-induced plasticity (TRIP) strengthening and the intrinsically brittle nature of deformation-induced alpha '-martensite (DIM) has been a long-standing dilemma in optimizing the strength-toughness synergy of austenitic steels. This has limited their potential use, particularly in energy absorption applications. Here, we propose a new strategy to minimize the negative effect of intrinsically brittle alpha '-martensite without limiting the TRIP. In this study, austenitic 321 stainless steel samples with different austenite grain sizes (AGSs) were fabricated to tailor the DIM morphology. The effect of the DIM morphology on the crack propagation energy was simultaneously evaluated. Electron channeling contrast imaging (ECCI) and selected area electron backscattered diffraction (EBSD) of the Charpy fractures reveals that lath-like alpha '-martensite effectively deflects cracks and increases the crack propagation energy (Ep). As a consequence, coarse-grained and ultra-coarse-grained (CG/UCG) steels with lath-like alpha '-martensite can simultaneously achieve high strength and crack propagation resistance, while ultra-fine-grained (UFG) steel with blocky DIM exhibits the lowest Ep. Furthermore, the morphology of DIM is controlled by its nucleation sites and adjacent crystallographic/phase boundaries. The twins or e-gamma boundaries promote the formation of lath-like alpha '-martensite. The gamma -> e ->alpha ' transformation sequence can be explained by the change in stacking fault energy (SFE), which provides further guidance for the design of austenitic steels with high strength and high toughness.