P10H cracking at HAZ
P10H cracking at HAZ
(OP)
Has anyone had any similar problems of cracking occurring at the HAZ of a P10H (or P8) T joint that is exposed to vibrations?
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RE: P10H cracking at HAZ
RE: P10H cracking at HAZ
RE: P10H cracking at HAZ
RE: P10H cracking at HAZ
RE: P10H cracking at HAZ
RE: P10H cracking at HAZ
Second comment - low cycle fatigue could be the cause of cracking. If the severity of stress or strain amplitude is below a threshold, there will be no source for fatigue crack initiation or propagation.
RE: P10H cracking at HAZ
RE: P10H cracking at HAZ
There are a number of welding paramters that can affect welding residual stress. This would explain why some fail in low cycle fatigue and some do not. Reinforcing fillets are advised. If reinforcing fillets cannot be employed, you may wish to peen to improve fatigue life and lower the residual tension weld stress at the crack origin site.
RE: P10H cracking at HAZ
1) Reduce the amplitude of the vibration, by damping it at its source and/or somewhere along its path to the fracture location.
2) Add gussets (if feasible) that act normally to the plane of vibration.
3) Reduce the geometric stress raiser by ensuring no undercut and then grinding a radius at the weld toe. Peening would be a further measure.
Note that adding more weld will not help; this is a base metal failure. The weld merely provides a stress raiser conveniently coinciding with the point of maximum stress caused by bending. In fact, it can exacerbate the situation by increasing the tensile residual stress.