Prevention of solidification cracking during pulsed laser beam welding

Effect of grain size on solidification cracking susceptibility of type 347 stainless steel during laser welding

Porosity Formation and Prevention in Pulsed Laser Welding

Porosity has been frequently observed in solidified, deep penetration pulsed laser welds. Porosity is detrimental to weld quality. Our previous study shows that porosity formation in laser welding is associated with the weld pool dynamics, keyhole collapse, and solidification processes. The objective of this paper is to use mathematical models to systematically investigate the transport phenome...

Initiation and growth kinetics of solidification cracking during welding of steel

Solidification cracking is a key phenomenon associated with defect formation during welding. To elucidate the failure mechanisms, solidification cracking during arc welding of steel are investigated in situ with high-speed, high-energy synchrotron X-ray radiography. Damage initiates at relatively low true strain of about 3.1% in the form of micro-cavities at the weld subsurface where peak volum...

Transport Phenomena and Keyhole Dynamics during Pulsed Laser Welding

Numerical and experimental studies were conducted to investigate the heat transfer, fluid flow, and keyhole dynamics during a pulsed keyhole laser welding. A comprehensive mathematical model has been developed. In the model, the continuum formulation was used to handle solid phase, liquid phase, and mushy zone during melting and solidification processes. The volume-of-fluid method was employed ...

Numerical Modeling of Heat Affected Zone Cracking Tendency during Laser and Hybrid Laser-Arc Welding Processes

A two-dimensional thermal elasto-plastic numerical model is developed by finite element method to analyze and compare the mechanical driving factor for heat affected zone (HAZ) liquation cracking during laser welding and hybrid laser-arc welding techniques. Calculations of transient temperatures and cooling rates are used in conjunction with solidification theory to analyze weld pool characteri...