Thermal Simulation Study of 900MPa Grade High-Strength Low Alloy Steel in Welding Procedures

2011 ◽  
Vol 704-705 ◽  
pp. 1128-1132
Author(s):  
Di Xin Yang ◽  
Yuan Fang Sun
Keyword(s):  
Alloy Steel ◽  
Heat Input ◽  
High Strength ◽  
Weld Bead ◽  
Peak Temperature ◽  
Welding Parameters ◽  
Chemical Compositions ◽  
Low Alloy Steel ◽  
Hydraulic Support ◽  
Welding Heat Input

Hydraulic support is an important part of fully mechanized equipments. The constructional steels of hydraulic support with international advanced level mainly adopt the high-strength welding structural steel with its tensile strength of more than 700~1000MPa.This paper analyzes the chemical compositions features of S890 high-strength low alloy steel for 900MPa grade.The Influence of welding parameters,peak temperature and on the microstructures and mechanical properties of welding HAZ of S890 high-strength low alloy steel were investigated by thermo-simulated tests, The influence of welding heat input on the mechanical behaviors of the welded joint was also investigated. The results show that the microstructures of S890 steel change from tempered martensite to bainite and a little ferrite , pearlitic when welding heat input changes from low to high, and accompany the austenite grains coarsening ,so the impact toughness and hardness of welding HAZ at lower peak temperatures and shorter are higher than that at higher peak temperature and long . Welding HAZ produced by the second weld bead will overlap partially with the HAZ produced by the first weld bead. In this area, primitive microstructure tempers again or partial re-phase transformations and re-cools,but the area involved in the overlap is limited,so the influence on the properties of S890 steel is not obvious. In covered arc welding,the influence on the welded join strength of S890 steel is not distinct when heat input change in a certain scope, but the plasticity of the welded join falls off steeply as heat input increases. Keywords: S890 steel; high-strength low alloy steel; weld performance; hydraulic supports

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.

Influence of Carbon Equivalent Value on the Weld Bead Bending Properties of High-Strength Low-Alloy Steel Plates

2017 ◽  
Vol 33 (4) ◽  
pp. 321-329 ◽  
Author(s):  
Ki Hyuk Kim ◽  
In Jun Moon ◽  
Ki Won Kim ◽  
Ki Bong Kang ◽  
Byung Gyu Park ◽  
...  
Keyword(s):  
Alloy Steel ◽  
High Strength ◽  
Weld Bead ◽  
Steel Plates ◽  
Carbon Equivalent ◽  
Low Alloy Steel ◽  
Bending Properties

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.

Sign in / Sign up

Export Citation Format

Share Document