Cracking the Initiation Mechanism of High Cu-Bearing Nitrogen-Alloyed Austenitic Stainless Steel in the Process of Hot Deformation
The cracking initiation mechanism of high Cu-bearing nitrogen-alloyed austenitic stainless steel was systematically investigated by using a Gleeble-1500D simulator under different strains and deformation temperatures in the hot deformation process. The cracking initiation process and microstructure...
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2018-10-01
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doaj-82454729d0894a27997045346fbf3d692020-11-25T01:27:06ZengMDPI AGMetals2075-47012018-10-0181081610.3390/met8100816met8100816Cracking the Initiation Mechanism of High Cu-Bearing Nitrogen-Alloyed Austenitic Stainless Steel in the Process of Hot DeformationXiao-Yang Fu0Pu-Cun Bai1Ji-Chun Yang2School of Material Science and Engineering, Inner Mongolia University of Technology, Hohhot 010051, ChinaSchool of Material Science and Engineering, Inner Mongolia University of Technology, Hohhot 010051, ChinaSchool of Material and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, ChinaThe cracking initiation mechanism of high Cu-bearing nitrogen-alloyed austenitic stainless steel was systematically investigated by using a Gleeble-1500D simulator under different strains and deformation temperatures in the hot deformation process. The cracking initiation process and microstructure variations were characterized by optical microscopy (OM), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) with energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). In the deformation process, Cu-rich and Cr-rich phases were found around the microscopic crack at the strain of 0.5. Cu content was found to be higher at the grain boundary than inside the grain. The equilibrium phase diagram calculated by Thermo-calc shows that Cu precipitates out in the form of an elementary substance below 1022 °C, when the Cu mass fraction reaches 5%. Meanwhile, dislocation walls and twin crystals were observed by TEM. The results show that the synergistic effect of the secondary phases, such as M23C6 precipitated along the grain boundary and stress concentration, lead to crack generation, which is lower at high temperature and low temperature and is higher at 1100 °C and increase as the strain increases.http://www.mdpi.com/2075-4701/8/10/816Cu-bearingnitrogen-alloyedaustenitic stainless steelcrackhot deformation |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Xiao-Yang Fu Pu-Cun Bai Ji-Chun Yang |
spellingShingle |
Xiao-Yang Fu Pu-Cun Bai Ji-Chun Yang Cracking the Initiation Mechanism of High Cu-Bearing Nitrogen-Alloyed Austenitic Stainless Steel in the Process of Hot Deformation Metals Cu-bearing nitrogen-alloyed austenitic stainless steel crack hot deformation |
author_facet |
Xiao-Yang Fu Pu-Cun Bai Ji-Chun Yang |
author_sort |
Xiao-Yang Fu |
title |
Cracking the Initiation Mechanism of High Cu-Bearing Nitrogen-Alloyed Austenitic Stainless Steel in the Process of Hot Deformation |
title_short |
Cracking the Initiation Mechanism of High Cu-Bearing Nitrogen-Alloyed Austenitic Stainless Steel in the Process of Hot Deformation |
title_full |
Cracking the Initiation Mechanism of High Cu-Bearing Nitrogen-Alloyed Austenitic Stainless Steel in the Process of Hot Deformation |
title_fullStr |
Cracking the Initiation Mechanism of High Cu-Bearing Nitrogen-Alloyed Austenitic Stainless Steel in the Process of Hot Deformation |
title_full_unstemmed |
Cracking the Initiation Mechanism of High Cu-Bearing Nitrogen-Alloyed Austenitic Stainless Steel in the Process of Hot Deformation |
title_sort |
cracking the initiation mechanism of high cu-bearing nitrogen-alloyed austenitic stainless steel in the process of hot deformation |
publisher |
MDPI AG |
series |
Metals |
issn |
2075-4701 |
publishDate |
2018-10-01 |
description |
The cracking initiation mechanism of high Cu-bearing nitrogen-alloyed austenitic stainless steel was systematically investigated by using a Gleeble-1500D simulator under different strains and deformation temperatures in the hot deformation process. The cracking initiation process and microstructure variations were characterized by optical microscopy (OM), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) with energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). In the deformation process, Cu-rich and Cr-rich phases were found around the microscopic crack at the strain of 0.5. Cu content was found to be higher at the grain boundary than inside the grain. The equilibrium phase diagram calculated by Thermo-calc shows that Cu precipitates out in the form of an elementary substance below 1022 °C, when the Cu mass fraction reaches 5%. Meanwhile, dislocation walls and twin crystals were observed by TEM. The results show that the synergistic effect of the secondary phases, such as M23C6 precipitated along the grain boundary and stress concentration, lead to crack generation, which is lower at high temperature and low temperature and is higher at 1100 °C and increase as the strain increases. |
topic |
Cu-bearing nitrogen-alloyed austenitic stainless steel crack hot deformation |
url |
http://www.mdpi.com/2075-4701/8/10/816 |
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