Constitutive response of welded HSLA 100 steel

Abstract

The dynamic mechanical behavior of a welded joint of high-strength, low alloy (HSLA) 100 steel was investigated by both quasistatic (103 s (1 ) and high strain rate (103 s (1 ) tension loadings at ambient and low temperatures. The constitutive responses for the microstructurally different weld and base steels, along with the interface, which included the heat-affected zone (HAZ), were analyzed and compared. This response is successfully modeled by the mechanical threshold stress (MTS) constitutive equation for different regions of the welded joint, which shows qualitatively different behavior. The necking and failure occurred uniformly within the weld metal but not in the HAZ. The main mechanism for the failure of the welded joints is void growth. Microstructural characterization revealed that the nucleation of voids occurred mainly at the interface between the base and the weld metal, and initiated at inclusions. Measurements of damage distributions across HAZ were made to evaluate the contribution of porosity variation to the constitutive response. In both the quasi-static and dynamic tests, the deformation localization in the form of necking first appeared in the weld metal. Fractographic observation demonstrates that void evolution is a dominant factor in the macroscopic mechanical response. The Gurson Á/Tvergaard model was included in the modeling effort to incorporate the effect of void opening on the mechanical response as well as tensile instability. The MTS constitutive model was successfully implemented to the tensile regime of loading. #

Microstructure and Mechanical Properties of Low-Carbon High-Strength Steel Fabricated by Wire and Arc Additive Manufacturing

“…Low-carbon high-strength steel has been applied in many fields such as shipbuilding, automobiles, mining instruments, and railways due to its unique characteristics of mechanical properties and weldability [1]. However, it is difficult to manufacture large scale fabrications with a complex structure by means of conventional methods, and it is also time consuming with high costs.…”

The Effect of Welding Parameters on Microstructural and Mechanical Properties of HSLA S960QL Type Steel with Submerged Arc Welding

“…While substantial improvements have been made in the thermomechanical processing of steels, the secret of the success of HSLA steels is in the micro alloying where the addition of small amounts of elements such as niobium, titanium or vanadium can make all the difference. They are designed to meet specific mechanical properties rather than a chemical composition [1][2][3][4][5][6][7][8][9][10][11][12][13].…”

The Ballistic Behavior of High Strength, Low Alloy-100 Steel at Sub-zero Temperatures

“…Over the past recent years, a number of studies have been accomplished on HSLA steels but these studies are mostly related to quasi-static and fatigue loadings and the strength of welded connections made of this type of alloys [6,7]. There are foot prints in the literature of studies on the dynamic behavior of HSLA steels [8,9]. The effect of heat treatment on microstructure and the properties of high strength low carbon steels have also been investigated [10][11][12][13].…”