Journal Of Applied and Computational Sciences in Mechanics

Journal Of Applied and Computational Sciences in Mechanics

Influence of Cooling Rate on Hardness and Machinability in Low-Carbon Steel WAAM

Document Type : Original Article

Authors
Mohammad Ebadi Tavallaei 1
Kiana Arteshyar 2
Mahdi Mazloom Farsibaf 2
Farhad kolahan 2
Sadegh Elhami 2
1 Mechanical Engineering Department, Ferdowsi University of Mashhad, Mashhad, Razavi Khorasan, Iran.
2 Mechanical Engineering Department, Ferdowsi University of Mashhad, Mashhad, Razavi Khorasan, Iran
10.22067/jacsm.2026.93580.1329
Abstract
Wire Arc Additive Manufacturing (WAAM), especially in its Metal Active Gas (MAG) form, has emerged as a promising technique for fabricating large and complex metal components. In this study, walls were built on ST37 steel substrates using ER70S-6 filler wire, with voltage and travel speed varied between 20–22 V and 100–200 mm/min, respectively. Hardness measurements revealed a gradient from 213.5 HV at the edges to 137.4 HV at the center, attributed to differing cooling rates. Rapid edge cooling led to fine-grained microstructures, while slower cooling in the center resulted in coarser grains. Optical microscopy confirmed a hypoeutectoid microstructure of ferrite and pearlite. Despite minor porosity, the produced walls showed a yield strength of 490 MPa—significantly higher than the 400 MPa of the base metal. These findings demonstrate the mechanical effectiveness of the WAAM-MAG process. However, the non-uniform hardness can impact machining performance, making tool selection and parameter optimization essential. Accurate assessment of hardness gradients is crucial for improving post-processing and achieving consistent component quality.
Keywords
Wire Arc Additive Manufacturing
Hardness Distribution
Microstructural and Mechanical Analysis
Low-carbon steel alloy
ER70S-6 wire filler
Subjects
[1] J. Harrington Jr., “Understanding the Manufacturing Process: Key to Successful CAD/CAM Implementation,” CRC Press, 2020.
[2]    S. Jung et al., “Is additive manufacturing an environmentally and economically preferred alternative for mass production?” Environmental Science & Technology, vol. 57, no. 16, pp. 6373–6386, 2023. https://doi.org/10.1021/acs.est.2c04927
[3] C. Maware et al., “Examining the progress in additive manufacturing in supporting lean, green and sustainable manufacturing: a systematic review,” Applied Sciences, vol. 14, no. 14, p. 6041, 2024. https://doi.org/10.3390/app14146041
[4] M. Armstrong, H. Mehrabi, and N. Naveed, “An overview of modern metal additive manufacturing technology,” Journal of Manufacturing Processes, vol. 84, pp. 1001–1029, 2022. https://doi.org/10.1016/j.jmapro.2022.10.060
[5] W. Huang et al., “Laser wire‑feed metal additive manufacturing of the Al alloy,” Optics & Laser Technology, vol. 134, p. 106627, 2021. https://doi.org/10.1016/j.optlastec.2020.106627
[6] M. M. Imran et al., “Advancements in 3D printing: Directed energy deposition techniques, defect analysis, and quality monitoring,” Technologies, vol. 12, no. 6, p. 86, 2024. https://doi.org/10.3390/technologies12060086
[7]    R. Bidulsky et al., “Coated metal powders for laser powder bed fusion (L‑PBF) processing: a review,” Metals, vol. 11, no. 11, p. 1831, 2021. https://doi.org/10.3390/met11111831
[8]    M. Sivakumar et al., “Directed energy deposition (DED) process,” in Advances in Additive Manufacturing, 2024, pp. 39–60. https://doi.org/10.1002/9781394238316.ch3
[9] S. Pattanayak and S. K. Sahoo, “Gas metal arc welding based additive manufacturing — a review,” CIRP Journal of Manufacturing Science and Technology, vol. 33, pp. 398–442, 2021. https://doi.org/10.1016/j.cirpj.2021.04.010
[10] S. Kumar, N. S. Madugula, N. Kumar, and J. Giri, “An extensive analysis of GTAW process and its influence on the microstructure and mechanical properties of SDSS 2507,” Journal of Materials Research and Technology, vol. 33, pp. 8675–8686, 2024. https://doi.org/10.1016/j.jmrt.2024.11.157
[11]  M. Mazloom Farsibaf et al., “Micro‑size A‑TIG modeling and RSM optimization for enhanced AISI304L DOP,” Welding International, vol. 39, no. 6, pp. 418–428, 2025. https://doi.org/10.1080/09507116.2025.2477012
[12]  H. Zhang et al., “Investigating the influence mechanism of different shielding gas types on arc characteristics and weld quality in TA2 laser–arc hybrid welding,” Metals, vol. 14, no. 8, p. 946, 2024. https://doi.org/10.3390/met14080946
[13]  N. Kumar et al., “Wire arc additive manufacturing – a revolutionary method in additive manufacturing,” Materials Chemistry and Physics, vol. 285, p. 126144, 2022. https://doi.org/10.1016/j.matchemphys.2022.126144
[14]  T. N. Wordofa and P. J. Ramulu, “Gas metal arc welding input parameters impacts on weld quality characteristics of steel materials: a comprehensive exploration,” Technology, vol. 3, no. 23, pp. 366–379, 2023. https://doi.org/10.21062/mft.2023.046
[15]  J. Vora et al., “Experimental investigations on mechanical properties of multi-layered structure fabricated by GMAW-based WAAM of SS316L,” Journal of Materials Research and Technology, vol. 20, pp. 2748–2757, 2022. https://doi.org/10.1016/j.jmrt.2022.08.074
[16]  P. Shukla et al., “The influence of GMAW correction parameters on stabilizing the deposition characteristics for wire arc additive manufacturing,” Journal of Manufacturing Processes, vol. 90, pp. 54–68, 2023. https://doi.org/10.1016/j.jmapro.2023.01.075
[17]  C. Su et al., “Effect of heat input on microstructure and mechanical properties of Al‑Mg alloys fabricated by WAAM,” Applied Surface Science, vol. 486, pp. 431–440, 2019. https://doi.org/10.1016/j.apsusc.2019.04.255
[18] M. Tongov et al., “Effect of heat input on microstructure and microhardness in WAAM,” Proceedings of the Bulgarian Academy of Sciences, vol. 77, no. 9, pp. 1340–1346, 2024. https://doi.org/10.7546/CRABS.2024.09.09
[19] V. Nagallapati et al., “Active and passive thermal management in wire arc additive manufacturing,” Metals, vol. 13, no. 4, p. 682, 2023. https://doi.org/10.3390/met13040682
[20]  D. Fan et al., “Residual stress and microstructure properties by trailing cooling of argon gas of wire and arc additive manufacturing,” Journal of Manufacturing Processes, vol. 77, pp. 32–39, 2022. https://doi.org/10.1016/j.jmapro.2022.03.007
[21]  S. Panicker et al., “Investigation of thermal influence on weld microstructure and mechanical properties in wire and arc additive manufacturing of steels,” Materials Science and Engineering: A, vol. 853, p. 143690, 2022. https://doi.org/10.1016/j.msea.2022.143690
[22]  R. Scharf‑Wildenhain et al., “Heat control and design‑related effects on the properties and welding stresses in WAAM components of high‑strength structural steels,” Welding in the World, vol. 67, no. 4, pp. 955–965, 2023. https://doi.org/10.1007/s40194-022-01450-x
[23]  P. H. G. Dornelas et al., “Development of a gas metal arc based prototype for direct energy deposition with micrometric wire,” Journal of Materials Research and Technology, vol. 30, pp. 3571–3583, 2024. https://doi.org/10.1016/j.jmrt.2024.04.056
[24]  K. Ginjupalli and N. P. Upadhya, “Surface roughness of implants: A review,” Trends in Biomaterials and Artificial Organs, vol. 25, no. 3, pp. 112–118, 2011.
[25]  A. Chmielewska and D. Dean, “The role of stiffness‑matching in avoiding stress shielding‑induced bone loss and stress concentration‑induced skeletal reconstruction device failure,” Acta Biomaterialia, vol. 173, pp. 51–65, 2024. https://doi.org/10.1016/j.actbio.2023.11.011
[26]  A. Chmielewska and D. Dean, “The role of stiffness‑matching in avoiding stress shielding‑induced bone loss and stress concentration‑induced skeletal reconstruction device failure,” Acta Biomaterialia, vol. 173, pp. 51–65, 2024. https://doi.org/10.1016/j.actbio.2023.11.011
[27]  M. Dekis et al., “Unveiling the characteristics of ER70S‑6 low carbon steel alloy produced by wire arc additive manufacturing at different travel speeds,” Metals and Materials International, vol. 31, no. 2, pp. 325–338, 2025. https://doi.org/10.1007/s12540-024-01766-x
[28]  S. Saravanan et al., “Assessment of the tribological behavior of WAAM‑fabricated SS316L through advanced ensemble machine learning predictions and RSM‑based optimization,” Journal of Materials Engineering and Performance, pp. 1–22, 2025. https://doi.org/10.1007/s11665-025-11691-8
[29]  W. Zhai, N. Wu, and W. Zhou, “Effect of interpass temperature on wire arc additive manufacturing using high‑strength metal‑cored wire,” Metals, vol. 12, no. 2, p. 212, 2022. https://doi.org/10.3390/met12020212
[30]  A. A. Kardak and G. B. Sinclair, “Stress concentration factors for ASTM E8/E8M‑16a standard round specimens for tension testing,” Journal of Testing and Evaluation, vol. 48, no. 1, pp. 711–719, 2020. https://doi.org/10.1520/JTE20190549
[31]  X. Chen et al., “Microstructure and mechanical properties of the austenitic stainless steel 316L fabricated by gas metal arc additive manufacturing,” Materials Science and Engineering: A, vol. 703, pp. 567–577, 2017. https://doi.org/10.1016/j.msea.2017.05.024
[32]  M. Shamir et al., “Assessment of mechanical and fatigue crack growth properties of wire+arc additively manufactured mild steel components,” Fatigue & Fracture of Engineering Materials & Structures, vol. 45, no. 10, pp. 2978–2989, 2022. https://doi.org/10.1111/ffe.13797
[33]  M. G. Ganesh et al., “Investigation on mechanical properties of ER70S‑6 copper‑coated steel wire sample produced by wire arc additive manufacturing (WAAM),” In International Conference on Trends in Automotive Parts Systems and Applications, SAE Technical Paper, 2024.
[34]  Y. Lu et al., “Comparative analysis of mechanical properties and microstructure of 7B52 aluminum alloy laser-MIG hybrid welding and MIG welding joints,” Metals, vol. 14, no. 10, 2024. https://doi.org/10.3390/met14101110
[35]  MM. Mukri et al., “Optimization of machining parameters in turning for different hardness using multi-objective genetic algorithm,” Journal of Mechanical Engineering (JMechE), vol. 20, no. 3, pp. 25-48, 2023. https://doi.org/10.24191/jmeche.v20i3.23899
[36]  I.-S. Kang et al., “Influence of the material mechanical properties on cutting surface quality during turning,” Processes, vol. 12, no. 6, p. 1171, 2024. https://doi.org/10.3390/pr12061171
[37]  I. Basso et al., “Influences of the workpiece material and the tool-surface engagement (TSE) on surface finishing when ball-end milling,” Journal of Manufacturing Processes, vol. 75, pp. 219-231, 2022. https://doi.org/10.1016/j.jmapro.2021.12.059
[38]  O. C. Ozaner et al., “The influence of the wire and arc additive manufacturing parameters on the surface irregularities,” Journal of Micromanufacturing, vol. 8, no. 1, 2024. https://doi.org/10.1177/25165984241306629
[39]  S. Saini, I. S. Ahuja, and V. S. Sharma, “Residual stresses, surface roughness, and tool wear in hard turning: A comprehensive review,” Materials and Manufacturing Processes, vol. 27, no. 6, pp. 583–598, 2012. https://doi.org/10.1080/10426914.2011.585505
[40]  Y. Kalinin et al., “Structure of high‑carbon steel after welding with rapid cooling,” Acta Metallurgica Slovaca, vol. 25, no. 2, pp. 114–122, 2019. https://doi.org/10.12776/ams.v25i2.1269
[41]  S. Jeong et al., “Effect of line‑heating on the microstructural and mechanical characteristics of 320‑MPa‑grade high‑strength hull plates,” Journal of Welding and Joining, vol. 40, no. 4, pp. 352–357, 2022. https://doi.org/10.5781/JWJ.2022.40.4.8
[42]  A. I. Albannai, “A brief review on the common defects in wire arc additive manufacturing,” International Journal of Current Science Research and Review, vol. 5, pp. 4556–4576, 2022. https://doi.org/10.47191/ijcsrr/V5-i12-19
[43]  K. L. M. Avegnon et al., “Porosity formation from disrupted gas flow in laser powder bed fusion of 316 stainless steel,” Journal of Manufacturing Processes, vol. 90, pp. 333–340, 2023. https://doi.org/10.1016/j.jmapro.2022.12.032
[44]  M. R. Zahidin et al., “Research challenges, quality control and monitoring strategy for wire arc additive manufacturing,” Journal of Materials Research and Technology, vol. 24, pp. 2769–2794, 2023. https://doi.org/10.1016/j.jmrt.2023.03.200
[45]  Y. Guo, “Microstructures and mechanical properties of ER70S‑6 steel fabricated by wire arc additive manufacturing,” 2025.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Send comment about this article
Enter Name.
Enter a valid email address.
Enter a vaid affiliation.
Enter comments (At leaset 10 words)
CAPTCHA Image
Enter Security Code Correctly.