Microstructure and Mechanical Properties of Medium Carbon Steel Deposits Obtained via Wire and Arc Additive Manufacturing Using Metal-Cored Wire

Zidong Lin,Marcel J.M Hermans,Wei Ya,Constantinos Goulas

doi:10.3390/met9060673

Zidong Lin, Marcel J.M Hermans + Show 2 more

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https://doi.org/10.3390/met9060673

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Abstract

Wire and arc additive manufacturing (WAAM) is a 3D metal printing technique based on the arc welding process. WAAM is considered to be suitable to produce large-scale metallic components by combining high deposition rate and low cost. WAAM uses conventional welding consumable wires as feedstock. In some applications of steel components, one-off spare parts need to be made on demand from steel grades that do not exist as commercial welding wire. In this research, a specifically produced medium carbon steel (Grade XC-45), metal-cored wire, equivalent to a composition of XC-45 forged material, was deposited with WAAM to produce a thin wall. The specific composition was chosen because it is of particular interest for the on-demand production of heavily loaded aerospace components. The microstructure, hardness, and tensile strength of the deposited part were studied. Fractography studies were conducted on the tested specimens. Due to the multiple thermal cycles during the building process, local variations in microstructural features were evident. Nevertheless, the hardness of the part was relatively uniform from the top to the bottom of the construct. The mean yield/ultimate tensile strength was 620 MPa/817 MPa in the horizontal (deposition) direction and 580 MPa/615 MPa in the vertical (build) direction, respectively. The elongation in both directions showed a significant difference, i.e., 6.4% in the horizontal direction and 11% in the vertical direction. Finally, from the dimple-like structures observed in the fractography study, a ductile fracture mode was determined. Furthermore, a comparison of mechanical properties between WAAM and traditionally processed XC-45, such as casting, forging, and cold rolling was conducted. The results show a more uniform hardness distribution and higher tensile strength of the WAAM deposit using the designed metal-cored wires.

Highlights

Additive manufacturing (AM) processes produce 3D components directly from dedicated 3DCAD models by depositing material layer-by-layer
Wire and arc additive manufacturing (WAAM) is an AM technique that combines an electric arc as a heat source and a consumable wire as feedstock
Metals 2019, 9, 673 high material utilization, and short production lead time compared to powder-based direct energy deposition (DED) techniques, WAAM has been considered for applications in the aerospace [3,4], automotive [1,5], and marine [6,7] sectors

Summary

Introduction

Additive manufacturing (AM) processes produce 3D components directly from dedicated 3DCAD models by depositing material layer-by-layer. Wire and arc additive manufacturing (WAAM) is an AM technique that combines an electric arc as a heat source and a consumable wire as feedstock It can be considered as a modification of the classical gas metal arc welding (GMAW) process. Some variants of GMAW, such as cold metal transfer (CMT) and tandem GMAW, have been created and used to improve the quality and efficiency of deposition in GMAW-based WAAM From these existing methods, the faster deposition rate of GMAW (up to 160 g/min) makes it the ideal candidate for the production of large-scale parts in short time spans [8,9], and it has become the most popular process in WAAM [10]. An example related to large-scale parts in the marine sector is the WAAMpeller, the world’s first class approved 3D printed ship propeller [11]

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