Influence of Welding Parameters and Filler Material on the Mechanical Properties of HSLA Steel S960MC Welded Joints

Abstract

This article provides an overview of the influence of welding parameters and filler material on changes in the heat-affected zone (HAZ) of thermo-mechanically controlled processed (TMCP) steel welded joints. The research focused on evaluating the effect of heat input and cooling rate on the width of the soft zone, which significantly affects the mechanical properties of welded joints. The negative effect of the soft zone is more pronounced as the thickness of the material decreases. Therefore, the object of this research was a 3-mm-thick sheet of S960MC steel welded by gas metal arc welding (GMAW) and metal-cored arc welding (MCAW) technology. Variable welding parameters were reflected in different heat input and cooling rate values, which led to a change in the properties of the HAZ and thus the mechanical properties of the welded joints. The changes in the HAZ were analyzed by microscopic analysis and mechanical testing. The measured results showed a significant effect of heat input on the cooling rate, which considerably affected the width of the soft zone in the HAZ and thus the overall mechanical properties of the welded joints.

Advanced High-Strength Steels for Automotive Applications: Arc and Laser Welding Process, Properties, and Challenges

“…Because of its excellent mechanical properties, DOMEX 700 is primarily used to fabricate cranes for the heavy construction industry. Mician et al [15] reported that the combination of qualities found in TMCP steels, including superior strength, enhanced toughness, and weldability, makes them a potential candidate for various applications, such as heavy vehicles crane booms, earthmovers, etc. Similarly, the S960MC steel grade meets these requirements.…”

“…The fine-grained microstructure generated by the TMCP method also ensures that S960MC steels have high strength and good formability. The Nb, Ti, and V elements play a predominant role because they generate dispersive precipitates which provide precipitation strengthening [15,16,56,57]. The precipitate strengthening supplied by Nb strengthens steel using carbonitrides particles.…”

“…Welding AHSS is frequently required to realize the full potential of these steels and to provide designers with more options. Numerous investigations by various authors [14,15,34,36,37,39,44,[64][65][66] have been conducted into welding AHSS, particularly on the use of gas GMAW and laser welding. The weldability of these steels was examined under various situations utilizing various welding methods, including laser welding, ultra-narrow gap laser welding, GTAW, controlled mode of metal transfer (CMT) during GMAW, and hybrid welding.…”

“…Mician et al [15] conducted GMAW on HSLA steel S960MC. The microhardness and microstructural investigations were used to establish the soft zone features.…”

Prediction of HAZ Microstructure and Hardness for Q960E Joints Welded by Triple-Wire GMAW Based on Thermal and Numerical Simulation

“…The engineering steels have changed from ordinary carbon steels (e.g., Q345 [8]) to high-strength steels (e.g., Q690 [9] or even Q960 [10]). For the welding of high strength steel, a lot of current research has focused on the process windows of different welding methods [11][12][13][14][15], the influence of alloying elements on weldability [16][17][18], the matching and upgrading of welding wire [19][20][21], and the failure of welded joints [22][23][24][25].…”