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Effect of Cu on the Microstructure and Mechanical Properties of a Low-Carbon Martensitic Stainless Steel

Reversed austenite is of vital importance in low-carbon martensitic stainless steel because it improves impact toughness. However, a proper amount of reversed austenite is obtained by tempering at a critical temperature, which reduces the strength of the steel. Therefore, how to improve strength–tou...

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Autores principales: Ma, Jun, Song, Yuanyuan, Jiang, Haichang, Rong, Lijian
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9787517/
https://www.ncbi.nlm.nih.gov/pubmed/36556655
http://dx.doi.org/10.3390/ma15248849
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author Ma, Jun
Song, Yuanyuan
Jiang, Haichang
Rong, Lijian
author_facet Ma, Jun
Song, Yuanyuan
Jiang, Haichang
Rong, Lijian
author_sort Ma, Jun
collection PubMed
description Reversed austenite is of vital importance in low-carbon martensitic stainless steel because it improves impact toughness. However, a proper amount of reversed austenite is obtained by tempering at a critical temperature, which reduces the strength of the steel. Therefore, how to improve strength–toughness matching is an important problem. Copper (Cu) is an effective strengthening element in steels. However, there is little in-depth discussion on the role of Cu on the microstructure and mechanical properties of low-carbon martensite steel. In this work, the effect of different Cu content on the reversed austenite formation, tensile strength, and impact toughness of a low-carbon martensitic stainless steel (0Cr13Ni4Mo) was systematically investigated through use of a transmission electron microscope (TEM), transmission Kikuchi diffraction (TKD), atom probe tomography (APT), and other characterization methods and mechanical property tests. The results showed that the addition of Cu decreased the phase transition temperatures of martensite and austenite and increased the volume fraction of the reversed austenite. APT results indicated that Cu-rich clusters first formed with alloying elements such as ferrum (Fe) and nickel (Ni) and then grew to be precipitates through rejection of the alloying elements. The Ni atoms diffused towards the interface between the precipitates and the martensite matrix, which provided heterogeneous nucleation sites for the reversed austenite. Cu precipitations strengthened tensile strength during tempering. However, it generated temper brittleness in the steel at a tempering temperature of 450 °C, resulting in the impact energy of the 3Cu-steel being only 7 J. A good combination with higher tensile strength (863 MPa) and ductility (192 J) was obtained when tempering at 600 °C in the presence of Cu-rich precipitates and a sufficient volume fraction of the reversed austenite. The results provide guidance for the design of steels with reversed austenite and Cu and promote the development of high-strength and high-toughness steels.
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spelling pubmed-97875172022-12-24 Effect of Cu on the Microstructure and Mechanical Properties of a Low-Carbon Martensitic Stainless Steel Ma, Jun Song, Yuanyuan Jiang, Haichang Rong, Lijian Materials (Basel) Article Reversed austenite is of vital importance in low-carbon martensitic stainless steel because it improves impact toughness. However, a proper amount of reversed austenite is obtained by tempering at a critical temperature, which reduces the strength of the steel. Therefore, how to improve strength–toughness matching is an important problem. Copper (Cu) is an effective strengthening element in steels. However, there is little in-depth discussion on the role of Cu on the microstructure and mechanical properties of low-carbon martensite steel. In this work, the effect of different Cu content on the reversed austenite formation, tensile strength, and impact toughness of a low-carbon martensitic stainless steel (0Cr13Ni4Mo) was systematically investigated through use of a transmission electron microscope (TEM), transmission Kikuchi diffraction (TKD), atom probe tomography (APT), and other characterization methods and mechanical property tests. The results showed that the addition of Cu decreased the phase transition temperatures of martensite and austenite and increased the volume fraction of the reversed austenite. APT results indicated that Cu-rich clusters first formed with alloying elements such as ferrum (Fe) and nickel (Ni) and then grew to be precipitates through rejection of the alloying elements. The Ni atoms diffused towards the interface between the precipitates and the martensite matrix, which provided heterogeneous nucleation sites for the reversed austenite. Cu precipitations strengthened tensile strength during tempering. However, it generated temper brittleness in the steel at a tempering temperature of 450 °C, resulting in the impact energy of the 3Cu-steel being only 7 J. A good combination with higher tensile strength (863 MPa) and ductility (192 J) was obtained when tempering at 600 °C in the presence of Cu-rich precipitates and a sufficient volume fraction of the reversed austenite. The results provide guidance for the design of steels with reversed austenite and Cu and promote the development of high-strength and high-toughness steels. MDPI 2022-12-11 /pmc/articles/PMC9787517/ /pubmed/36556655 http://dx.doi.org/10.3390/ma15248849 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Ma, Jun
Song, Yuanyuan
Jiang, Haichang
Rong, Lijian
Effect of Cu on the Microstructure and Mechanical Properties of a Low-Carbon Martensitic Stainless Steel
title Effect of Cu on the Microstructure and Mechanical Properties of a Low-Carbon Martensitic Stainless Steel
title_full Effect of Cu on the Microstructure and Mechanical Properties of a Low-Carbon Martensitic Stainless Steel
title_fullStr Effect of Cu on the Microstructure and Mechanical Properties of a Low-Carbon Martensitic Stainless Steel
title_full_unstemmed Effect of Cu on the Microstructure and Mechanical Properties of a Low-Carbon Martensitic Stainless Steel
title_short Effect of Cu on the Microstructure and Mechanical Properties of a Low-Carbon Martensitic Stainless Steel
title_sort effect of cu on the microstructure and mechanical properties of a low-carbon martensitic stainless steel
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9787517/
https://www.ncbi.nlm.nih.gov/pubmed/36556655
http://dx.doi.org/10.3390/ma15248849
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