Unveiling the Characteristics of ER70S-6 low Carbon Steel Alloy Produced by wire arc Additive Manufacturing at Different Travel Speeds

Abstract

Wire Arc Additive Manufacturing (WAAM) produces metal components with crucial properties dependent on process parameters. Understanding the effects of these parameters on microstructure and mechanical properties is vital for optimizing WAAM. This study investigated the impact of varying travel speeds (TS) on the microstructure and mechanical properties of low carbon steel ER70S-6 alloy produced by WAAM process. The hypothesis centred on the impact of different TS values on heat input (HI) and cooling rates, and the subsequent effects on the resulting microstructure and mechanical properties of the deposited material. ER70S-6 alloy was deposited at three different TS: 120, 150, and 180 mm/min. Microstructure and mechanical properties (microhardness, tensile strength, elongation) were evaluated for each TS condition. Distinct microstructures were observed in the deposited samples, influenced by cooling rates at different TS. Distinct microstructures emerged in different regions of the deposits due to varying cooling rates at different TS. Higher TS (180 mm/min) significantly reduced pores and cracks while enhancing yield strength (YS) and ultimate tensile strength (UTS) up to 25.2 ± 0.77% elongation and 502.3 ± 3.17 MPa UTS, respectively. However, UTS remained slightly lower (93%) than the catalogued value for ER70S-6 (540 MPa), indicating a mild softening effect. TS significantly influenced the microstructure and mechanical properties of WAAM-produced ER70S-6 alloy. This study provides key insights into optimizing WAAM parameters for low carbon steel, paving the way for improved component production for diverse industrial applications.