Optimization of the tensile-shear strength of laser-welded lap joints of ultra-high strength abrasion resistance steel

    
    Introduction
    
    Laser welding technology has been increasingly utilised in recent times in order to join sheet metals and plates of materials such as ultra-high abrasion resistance steel. Laser welding technology allows for the achievement of high-strength welded joints with a high level of precision, particularly when used in conjunction with lap joints. Lap joints are considered to be more structurally sound than other types of joints. However, the tensile-shear strength of laser-welded lap joints of ultra-high abrasion resistance steel is greatly affected by the welding parameters available, such as welding speed, laser power, peak power, etc. Various studies have been undertaken to optimize these parameters in order to reduce the occupied welding area, improve welding stability and maximize the tensile-shear strength of the weld joints.
    
    Overview of Laser Welding Technology
    
    Laser welding, which also known as laser beam welding (LBW), is a welding process in which a laser beam is used to generate sufficient heat energy to melt and join two pieces of metal. The laser beam intensity is inherently determined by the welding power, which is then varied according to the desired welding speed and penetration depth. This makes laser welding an efficient means of cutting and fusing materials when a high degree of precision is needed. The technology has been increasingly utilized in joining dissimilar metals, and also to weld metals with different thermal characteristics, such as ultra-high abrasion resistance steels, without inducing thermal stress distortions.
    
    Optimizing the Welding Parameters of Lap Joints
    
    Optimized welding parameters are essential to maximize the tensile-shear strength of laser-welded lap joints of ultra-high abrasion resistance steels. In particular, the welding speed, laser power, and peak power can have significant effects on the tensile-shear strength of the weld joint, with significant reductions being seen when some welding parameters are not adequately addressed. As such, various studies have been conducted to optimize these parameters so as to reduce the welding area, improve welding stability, and maximize the tensile-shear strength of the weld joints.
    
    One of the most important welding parameters for ultra-high abrasion resistance steels is the welding speed. The welding speed needs to be slow enough to ensure the necessary welding temperature is achieved, while still being fast enough to prevent the formation of micro-cracks due to a high temperature gradient. A low welding speed will reduce the penetration depth of the weld, while a high welding speed makes the weld surface rough and unstable. Hence, selecting an appropriate welding speed is essential to optimizing the tensile-shear strength of laser-welded lap joints of ultra-high abrasion resistance steels.
    
    Other essential welding parameters are the laser power and peak power. A higher laser power and peak power can improve the welding efficiency and penetration depth of the weld joint. However, too high of a power value can lead to overheating of the weld surface, resulting in the formation of micro-cracks that can cause a considerable reduction in the tensile-shear strength of the weld joint. Hence, it is necessary to select a suitable laser power and peak power that will ensure the appropriate welding temperature is achieved for the specific materials being welded.
    
    Conclusion
    
    In conclusion, laser-welded lap joints of ultra-high abrasion resistance steels can be optimized to maximize their tensile-shear strength by carefully selecting the appropriate welding parameters. In particular, the welding speed, laser power, and peak power should be adjusted in order to reduce the welding area, improve weld stability and achieve an optimal tensile-shear strength. Adequate knowledge of the technology and the materials being welded is essential for the optimization of the welding process, thus ensuring a structurally sound weld joint with high-performing tensile-shear strength.

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