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Study on SLM Forming Process, Residual Stress and Thermal Fatigue of 24CrNiMo Alloy Steel

The selective laser melting (SLM) forming process of 24CrNiMo alloy steel was optimized by orthogonal experiment. The density and microstructure of the sample were analyzed, and the optimized process parameters were as follows: laser power 300 W, scanning speed 530 mm/s. The 24CrNiMo alloy steel sam...

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Autores principales: Zhao, Yongsheng, Ding, Chenggang, Chen, Hui, Chen, Yong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8401313/
https://www.ncbi.nlm.nih.gov/pubmed/34442905
http://dx.doi.org/10.3390/ma14164383
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author Zhao, Yongsheng
Ding, Chenggang
Chen, Hui
Chen, Yong
author_facet Zhao, Yongsheng
Ding, Chenggang
Chen, Hui
Chen, Yong
author_sort Zhao, Yongsheng
collection PubMed
description The selective laser melting (SLM) forming process of 24CrNiMo alloy steel was optimized by orthogonal experiment. The density and microstructure of the sample were analyzed, and the optimized process parameters were as follows: laser power 300 W, scanning speed 530 mm/s. The 24CrNiMo alloy steel samples were prepared with optimized parameters. The relationship between residual stress and thermal fatigue and the effect of stress-relieving annealing (SR) on residual stress were analyzed. The density of the sample was found to increase at first and then to decrease with the increase of laser power and then to decrease with the increase of scanning speed. Increasing the laser power and scanning speed widened and deepened the weld. Under the optimized process window, the formability of 24CrNiMo alloy steel samples was improved significantly. The residual stress distribution was tensile stress, which had a negative effect on the thermal fatigue properties of the sample. After SR, the residual stress changed to compressive stress, which had a positive effect on the thermal fatigue properties of the samples. Compared with the deposited state, the thermal fatigue cracks were significantly shortened after SR, which was able to further promote the improvement of thermal fatigue performance. The gradient residual stress test showed that the gradient residual stress in the edge region and the central region of the deposited sample had the same trend, and decreased gradually from the surface layer to the base layer.
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spelling pubmed-84013132021-08-29 Study on SLM Forming Process, Residual Stress and Thermal Fatigue of 24CrNiMo Alloy Steel Zhao, Yongsheng Ding, Chenggang Chen, Hui Chen, Yong Materials (Basel) Article The selective laser melting (SLM) forming process of 24CrNiMo alloy steel was optimized by orthogonal experiment. The density and microstructure of the sample were analyzed, and the optimized process parameters were as follows: laser power 300 W, scanning speed 530 mm/s. The 24CrNiMo alloy steel samples were prepared with optimized parameters. The relationship between residual stress and thermal fatigue and the effect of stress-relieving annealing (SR) on residual stress were analyzed. The density of the sample was found to increase at first and then to decrease with the increase of laser power and then to decrease with the increase of scanning speed. Increasing the laser power and scanning speed widened and deepened the weld. Under the optimized process window, the formability of 24CrNiMo alloy steel samples was improved significantly. The residual stress distribution was tensile stress, which had a negative effect on the thermal fatigue properties of the sample. After SR, the residual stress changed to compressive stress, which had a positive effect on the thermal fatigue properties of the samples. Compared with the deposited state, the thermal fatigue cracks were significantly shortened after SR, which was able to further promote the improvement of thermal fatigue performance. The gradient residual stress test showed that the gradient residual stress in the edge region and the central region of the deposited sample had the same trend, and decreased gradually from the surface layer to the base layer. MDPI 2021-08-05 /pmc/articles/PMC8401313/ /pubmed/34442905 http://dx.doi.org/10.3390/ma14164383 Text en © 2021 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
Zhao, Yongsheng
Ding, Chenggang
Chen, Hui
Chen, Yong
Study on SLM Forming Process, Residual Stress and Thermal Fatigue of 24CrNiMo Alloy Steel
title Study on SLM Forming Process, Residual Stress and Thermal Fatigue of 24CrNiMo Alloy Steel
title_full Study on SLM Forming Process, Residual Stress and Thermal Fatigue of 24CrNiMo Alloy Steel
title_fullStr Study on SLM Forming Process, Residual Stress and Thermal Fatigue of 24CrNiMo Alloy Steel
title_full_unstemmed Study on SLM Forming Process, Residual Stress and Thermal Fatigue of 24CrNiMo Alloy Steel
title_short Study on SLM Forming Process, Residual Stress and Thermal Fatigue of 24CrNiMo Alloy Steel
title_sort study on slm forming process, residual stress and thermal fatigue of 24crnimo alloy steel
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8401313/
https://www.ncbi.nlm.nih.gov/pubmed/34442905
http://dx.doi.org/10.3390/ma14164383
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