Cracked welds in EN24T/ Mild steel
Cracked welds in EN24T/ Mild steel
(OP)
A split ring (made from 25mm section EN24T)has two 10mm M/S lugs welded on either side of the 5mm split. A component is placed in the ring and held in place via an M10 bolt through the lugs - closing the split together. The jig and component are placed in an oven at 165degC for 8 hours. When removing from the oven, the welds have split.
The welds were produced with a 4mm M/S electrode (arc) at approx. 170Amps - penetration seems good, and the weld solid - no cavities or slag in the weld.
Can anybody tell me why please??
The welds were produced with a 4mm M/S electrode (arc) at approx. 170Amps - penetration seems good, and the weld solid - no cavities or slag in the weld.
Can anybody tell me why please??





RE: Cracked welds in EN24T/ Mild steel
RE: Cracked welds in EN24T/ Mild steel
RE: Cracked welds in EN24T/ Mild steel
The EN24 is a British grade of AISI Type 4140 alloy steel. If you did not use preheat, I would suspect that the cause of the weld failure was underbead cracking due to the formation of martensite (locally hardened zone) in the 4140 alloy steel HAZ.
A preheat of 200 deg C should correct this problem provided the filler metal is compatible for this application.
RE: Cracked welds in EN24T/ Mild steel
RE: Cracked welds in EN24T/ Mild steel
Is this a single-pass weld? I'll bet it is.