Problems during solution treatment of stainless steel welds
Thread Content
When the stainless steel weld is subjected to solution treatment in the welding area, could this simultaneously affect the carbon precipitation in the surrounding metal sheets, thereby causing new areas of \"intergranular corrosion\" to form around the weld? The planned solution treatment involves heating to 1100 degrees, with a duration of 16 minutes; the plate thickness is 8 mm. However, there is a concern that new areas of carbon precipitation may form around the heated zone, resulting in new areas of intergranular corrosion!
There is indeed this issue; a better approach is to carry out overall solution treatment or control the input amount during welding
Controlling the input amount during overall solution treatment or welding is ________ Overall solution treatment is very difficult; the drum used for this process is even larger than those in concrete mixers, making it quite troublesome to operate! Also, how exactly is it done to control the input amount during welding?
To prevent and reduce intergranular corrosion at welding joints, common preventive measures include: (1) using low-carbon or ultra-low-carbon welding materials such as A002, or welding rods containing stabilizing elements like titanium and niobium, such as A137 and A132； (2) A certain amount of ferrite-forming elements are introduced into the weld from the welding wire or electrode, resulting in a dual-phase structure of austenite + ferrite in the weld metal (the ferrite content is generally controlled at 4-12%) ； (3) Reduce overheating of the welding pool by using a lower welding current and a faster welding speed, thereby accelerating the cooling rate ； (4) Perform post-weld stabilization annealing on weldments with high requirements for intergranular corrosion resistance.
The original welding solution treatment process was as follows: 1. First, use air gouging to clean the existing weld roots, then use a grinder to remove the carburized layer and polish it until it has a metallic shine. 2. Use A132 welding rod for repair welding; carefully grind each layer of weld with a angle grinder to prevent slag inclusions. 3. After welding, carry out solution treatment by heating the weld area to 1100±10°C using oxygen-acetylene (as measured with a temperature detector), and maintain this temperature for 16 minutes (the typical holding time is 1–3 times the thickness of the material). Once the time is up, cool it rapidly with water. —————— Kind sir upstairs, could you please take a look and see what the problem is? What would be better to do?
(4) Perform post-weld stabilization annealing on weldments with high requirements for intergranular corrosion resistance. _____________________ Isn’t intergranular corrosion more likely to occur during the annealing process?