Key Points and Precautions for Welding Stainless Steel Air Electric Heaters:
I. Preparation before welding
1. According to the product drawing requirements, use mechanical processing methods to remove the stainless steel composite layer at the joint, and open appropriate grooves for butt welds.
2. Clean the area 10-20mm wide on both sides of the weld, using a wire brush or grinding to remove oxides, rust, oil, moisture, and other substances that affect welding quality.
3. Assemble according to the product drawing, use tack welding on the carbon steel side with electrodes. The tack welder should have a valid position operation certificate to ensure the quality of tack welding. The effective length of tack welding is 25-30mm.
II. Welding process
1. Welding process for butt joints of stainless steel composite steel plate
1.1 Base carbon steel welding
1.1.1 Use submerged arc automatic welding method, weld one layer on the front side, then turn over and use carbon arc gouging to back gouge on the reverse side, then seal weld one layer. Welding specifications are as follows:
Position Welding wire Flux Wire diameter Arc voltage Welding current Welding speed
Front H08A J431 φ5mm 31-33V 500-550A 44-46 cm/min
Reverse H08A J431 φ5mm 32-34V 580-620A 44-46 cm/min
1.1.2 Clean slag after welding and grind.
1.1.3 After welding, perform X-ray sampling inspection with a sampling ratio of 10-20%, or use UT flaw detection.
1.2 Transition layer welding
Use CO2 semi-automatic gas shielded welding method, weld one layer. Welding specifications are selected as follows:
Flux-cored wire TS-309
Wire diameter φ1.2 (MM)
Arc voltage 19-21V
Welding current 130-150A
1.3 Cladding layer welding
Use CO2 semi-automatic gas shielded welding method, weld one layer. Welding specifications are as follows:
Flux-cored wire TS-316L
Wire diameter φ1.2 (MM)
Interpass temperature 150℃
