Post weld heat treatment
Butt weld and groove weld are two common types of weld joints used in welding processes. A butt weld is a type of weld where two pieces of metal are joined together along their edges in a single plane, creating a smooth, flush surface. On the other hand, a groove weld is a type of weld where a groove or channel is created in one or both of the pieces being joined, and the filler material is deposited into the groove to create the weld. Both types of weld joints are used in various applications depending on the specific requirements of the project.
It is one way to "Stress Relieve" the weld joint. As the weld metal metal cools it contracts and hammering on the weld expands it. On thick sections it is done after every layer of weld. Often used when welding cast iron or other metals with a low COE (Coefficient of Expansion).
The required size for a seal weld per AISC is eighteen foot length. AISC also specifies minimum weld size based on the thicknesses of the members joined.
wildly welding main pipe the are fillet weld or butweld
post weld heat treatment is done on the weld areas after welding, to remove the residual stress present in the welded part formed during the welding process, it prevents to cause brittle fracture in a metal
AWS D1.1; 5.8 "Stress-Relief Heat Treatment"
Post weld heat treatment
Post weld heat treat is done to bring back strength properties lost during welding. It is not related to non destructive testing
John Robert Barclay has written: 'The effect of post weld heat treatment on high strength ferrous weld metals'
heating then controlled cooling of a weld to reduce stress
PWHT is a form of stress relief, other forms can be as simple as smacking your structural weld with a hammer. PWHT re-aligns metallic molicules (face centered) to similar configurations as before rapid heating and cooling occured.
Cooling correction refers to the adjustment made to account for the cooling effect present in a heat-affected zone during welding. It helps to ensure the correct temperature and cooling rate for the welded material, preventing issues such as cracking or distortion in the final weld. The correction is typically applied by controlling the preheat temperature, post-weld heat treatment, or the welding technique itself.
post heating : after completion of weld is not cool below to preheat or room temp. further it is heat by applying addition heating system to certain period of time and temperature to evalute hydrogen from weld metal.
You don't. You will never keep the tooth profiles right and will screw up the heat treatment. Get another gear!
no some of the heat is radiated away in forms of light and heat waves
It is the heat affected zone. It differs in every weld. but a good rule of thumb is .25" on either side of the weld