Is Inconel 600 Prone to Hot Cracking After Welding?
Yes, Inconel 600 can be susceptible to hot cracking (solidification cracking) during welding, especially in the weld metal and heat‑affected zone (HAZ). However, the susceptibility depends on several factors, including welding process, filler metal, heat input, and joint design.
1.Key Reasons for Hot Cracking Susceptibility
High nickel content leads to a narrow solidification range, which can promote hot cracking.
Impurities such as sulfur (S) and phosphorus (P) can form low‑melting‑point eutectics at grain boundaries, increasing cracking risk.
Grain growth in the HAZ can create paths for crack propagation.
High heat input during welding exacerbates segregation and grain growth, further increasing the likelihood of hot cracking.
2.Factors That Reduce Hot Cracking Risk
Using low‑sulfur, low‑phosphorus filler metals such as ERNiCr‑3 (Inconel 82) or ENiCrFe‑3 (Inconel 182).
Controlling heat input (typically 100–150 kJ/in for GTAW/GMAW).
Using proper joint design to minimize restraint.
Employing short arc lengths and rapid travel speeds to reduce grain growth.
Post‑weld heat treatment (PWHT) is generally not required for Inconel 600 and may even reduce corrosion resistance, but stress relief can help in some cases.
Summary for Hot Cracking
Inconel 600 does have a tendency to hot crack during welding, particularly with high heat input or improper filler metals.
However, with proper welding procedures, low‑impurity fillers, and controlled heat input, hot cracking can be effectively minimized.
