What is Post-Heating in Welding?

Post-heating is the process of applying heat to a welded joint after welding, brazing, soldering, or thermal spraying. The purpose of post-heating is to relieve stress, temper the metal, or anneal the weld.

When post-heating is necessary?

Post-heating is often necessary when welding:

high-strength steels
nickel alloys
titanium

These materials are susceptible to cracking if they are not heated properly after welding. Post-heating can also help improve the appearance of welds on stainless steel and aluminum.

How to post-heat?

Post-heating is typically done with a torch, furnace, or other heat sources. The temperature and duration of the post-heat will depend on the material being welded and the welding process used.

What are the risks of not post-heating?

Not post-heating properly can lead to cracking, warping, or other problems with the weld. If you are unsure about whether or not post-heating is necessary, consult your welding engineer or WPS.

What is post heat used for in welding?

The main purpose of post-heat is to relieve stress in the welded joint. It can also be used to temper the metal or anneal the weld.

How much post heat is needed for welding?

The amount of post heat required will depend on the material being welded and the welding process used.

What is preheating in welding?

Preheating is the process of applying heat to a weld joint before welding. The purpose of preheating is to slow down the cooling rate of the weld metal and heat-affected zone, which helps to prevent cracking.

When is preheating necessary?

Preheating is often necessary when welding high-strength steels, nickel alloys, and titanium. These materials are susceptible to cracking if they are not heated properly before welding. Preheating can also help improve the appearance of welds on stainless steel and aluminum.

How to preheat?

Preheating is typically done with a torch, furnace, or other heat sources. The temperature and duration of the preheat will depend on the material being welded and the welding process used. Consult your welding engineer or WPS for specific preheating instructions.

What are the risks of not preheating?

The amount of preheating required will depend on the material being welded and the welding process used.

What is the difference between post-heating and PWHT?

PWHT (post-weld heat treatment) is a controlled process that applies heat to the weld joint after welding. The purpose of PWHT is to relieve stress, temper the metal, or anneal the weld.

Post-heating is similar to PWHT, but it is not as controlled or regulated.