scholarly journals The impact of heat input on the mechanical properties and microstructure of High Strength Low Alloy steel welded joint by GMA welding process

2021 ◽  
Vol 9 (3) ◽  
pp. 299-310 ◽  
Author(s):  
Saadat Ali Rizvi ◽  
Rajnish Singh ◽  
Saurabh Kumar Gupta
Keyword(s):  
Mechanical Properties ◽  
Alloy Steel ◽  
Heat Input ◽  
Gma Welding ◽  
Hsla Steel ◽  
Welding Process ◽  
Welding Current ◽  
High Strength ◽  
Low Alloy Steel ◽  
The Impact

The basic aim of this study was to find a relationship between heat input and mechanical properties of high strength low alloy steel (HSLA) welded joints and also elaborate its effect on microstructure. The combined effect of welding current, voltage and speed i.e. Heat Input on mechanical properties of High Strength Low Alloy Steel (ASTM A242 type-II) weldments have been studied in the present work. HSLA steel work pieces were welded by Gas metal arc welding (GMAW) process under varying welding current, arc voltage, and welding speed. Total nine samples were prepared at different heat input level i.e. 1.872 kJ/mm, 1.9333 kJ/mm, 2.0114 kJ/mm, 2.1 kJ/mm, 2.1956 kJ/mm, 2.296 kJ/mm, 2.4 kJ/mm, 2.5067 kJ/mm and 2.6154 kJ/mm It was observed that as heat input increases the ultimate tensile strength and microhardness of weldment decreased while impact strength increased and it was also observed that on increasing the heat input grain size of microstructure tends to coarsening it is only due to decreasing in cooling rate.

Interactions of the process parameters and mechanical properties of laser butt welds in thin high strength low alloy steel plates

2020 ◽  
Vol 234 (5) ◽  
pp. 665-680 ◽  
Author(s):  
Patricio Gustavo Riofrío ◽  
Carlos Alexandre Capela ◽  
José AM Ferreira ◽  
Amilcar Ramalho
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Laser Welding ◽  
Alloy Steel ◽  
Heat Input ◽  
High Strength ◽  
Welding Parameters ◽  
Bead Geometry ◽  
Low Alloy Steel ◽  
Weld Bead Geometry

High strength low alloy steels subjected to the thermomechanical control process present excellent strength–toughness combination, high strength/weight ratio, and weldability. Therefore, they are widely used in structural components, such as pressure vessels, oil/gas transportation pipes, lifting equipment, vehicles, shipbuilding and offshore industries, and in the automotive industry where low thickness (0.8–3 mm thickness) is of great importance. Usually, these steels are welded by conventional gas metal arc welding, which creates wide heat-affected zones, large residual stresses, and distortion in the welded parts. Laser welding is nowadays an alternative process to weld high strength low alloy steel parts due to its advantages. The aim of this work is to understand the effect of process parameters on defects, weld bead geometry, microstructure, and mechanical properties, namely hardness and tensile strength. We identify the main laser welding parameters and their influence on the weld bead geometry and defects, for a 3 mm thick high strength low alloy steel welded under a maximum power of 2 kW. A cross section of the weld seam was optimized achieving a good geometry without porosity. The threshold value of the heat input to achieve complete penetration was determined for different focus diameters. The microstructure, size, and hardness of the heat-affected zone and of the fusion zone are strongly influenced by the heat input. The values of the tensile strength achieved in butt welds were close to the base metal by an appropriate selection of the laser welding parameters and the heat input.

Effect of the Strain Rate on Mechanical Properties and Microstructure of High Strength Low Alloy Steel HC340LA

2012 ◽  
Vol 217-219 ◽  
pp. 467-470
Author(s):  
Xiao Hang Liu ◽  
Wen Jing Yuan ◽  
Hao Bin Tian ◽  
Fa Xi Diao
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Strain Rate ◽  
Alloy Steel ◽  
High Speed ◽  
Hsla Steel ◽  
High Strength ◽  
Static Tension ◽  
Low Alloy Steel

The mechanical properties and microstructure of the high strength low alloy HC340LA were obtained with different strain rate. The research shows that the better plasticity, higher tensile strength and yield ratio can be found in high speed tensile state than in quasi-static tension. The plasticity and tensile strength decrease with the increasing of the strain rate during the high speed tension. With the increasing of the strain rate, the grain size of the ferrite decreases and its distribution is uneven, and the grain boundaries increases. The HSLA steel HC340LA submit to obvious Ductile Frecture mechanism. The size of the dimples is more uniform, bigger and deeper with the strain rate 50 s-1 than with the strain rate 200 s-1. Therefore, the higher strain rate with over strain rate 50 s-1 has less Superscript textcontribution to the improvement of plasticity of the HSLA steel HC340LA.

scholarly journals Study the Effect of Welding Heat Input on the Microstructure, Hardness, and Impact Toughness of AISI 1015 Steel

2018 ◽  
Vol 14 (1) ◽  
pp. 118-127 ◽  
Author(s):  
Emad Kh. Hamd ◽  
Abbas Sh. Alwan ◽  
Ihsan Khalaf Irthiea
Keyword(s):  
Corrosion Rate ◽  
Weld Joint ◽  
Heat Input ◽  
Plate Thickness ◽  
Welding Process ◽  
Welding Current ◽  
Low Carbon ◽  
Mig Welding ◽  
The Impact ◽  
Weld Heat

In the present study, MIG welding is carried out on low carbon steel type (AISI 1015) by using electrode ER308L of 1.5mm diameter with direct current straight polarity (DCSP). The joint geometry is of a single V-butt joint with one pass welding stroke for different plate thicknesses of 6, 8, and 10 mm. In welding experiments, AISI 1015 plates with dimensions of 200×100mm and edge angle of 60o from both sides are utilized. In this work, three main parameters related to MIG welding process are investigated, which are welding current, welding speed, heat input and plate thickness, and to achieve that three groups of plates are employed each one consists of three plates. The results indicate that increasing the weld heat input (through changing the current and voltage) leads to an increase in widmanstatten ferrite (WF), acicular ferrite (AF) and polygonal ferrite (PF) in FZ region, and a reduction in grain size. It is observed that the micro-hardness of welded AISI 1015 plate increases as the weld heat input decreases. As well as increasing the weld heat input results in an increase in the width of WM and HAZ and a reduction in the impact energy of the weld joint of AISI 1015 at WM region. Also, it is noted the corrosion rate of weld joint increases with increase of Icorr due to increasing in welding current (heat input), corrosion rate increased up to (0.126µm/yr.) with increasing of heat input up to (1.27 KJ/mm).  

Sign in / Sign up

Export Citation Format

Share Document