Enhancing mechanical properties of low-carbon steel through wire arc direct energy deposition and in situ powder addition: experimental and numerical analysis

This study investigates the effect of wire arc direct energy deposition (WADED) of low-carbon steel on mild steel substrates, focusing on temperature distribution, distortion analysis, and the in situ addition of micropowders to enhance mechanical properties. Experimental and numerical analyses were conducted to compare peak temperatures and distortion between simulated and actual WADED samples. Results showed a close correlation between experimental thermography (using a long-wave infrared (LWIR) high-temperature camera) and finite element analysis (FEA) of the multilayer-deposited wall, with peak temperatures progressively increasing with each layer. Distortion analysis reveals maximum distortion of approximately 4 mm, attributed to local heating and cooling effects during deposition on a 6-mm thick substrate. Additionally, simulations indicate an optimal substrate thickness of 8 mm for minimizing distortion to approximately 1 mm. Furthermore, the study explores the effects of adding titanium micropowders between deposition layers, revealing modifications in microstructural characteristics, microhardness, and mechanical properties such as yield strength and ultimate tensile strength. Charpy impact testing demonstrates that despite increased hardness and strength, the toughness is maintained, attributed to retained austenite and titanium precipitates. SEM analysis confirms ductile fracture patterns in both as-deposited and titanium-added samples. These findings contribute to a deeper understanding of the WADED process and highlight the potential for enhancing mechanical properties through in situ powder alloying, with implications for applications in shipbuilding and other industries.