- SS 304 plate belongs to 0Cr18Ni9 series austenitic stainless steel, good weldability.
- cutting the plasma can be cut;
- electrode arc welding
Selection of A132; dissimilar steel welding selection A312;
Welder: DC reverse, Panasonic 400AT3 DC arc welding machine;
TIG welding (TIG welding)
Use ER308 (0Cr20Ni10) wire; Φ2.4
Dissimilar steel welding use ER309 (0Cr23Ni13) wire;
Protection gas: pure argon;
Welder: DC is positive, Panasonic 400TX3 DC pulse TIG arc welder;
solid wire MIG welding
Use solid ER308 (0Cr20Ni10) wire; Φ1.0 / 1.2
Dissimilar steel welding use solid ER309 (0Cr23Ni13) wire;
Shield gas: 98% Ar + 2% O2;
Welder: DC reverse, Panasonic 500GL3 pulse MIG / MAG / CO2 arc welding machine;
drug heart wire CO2 welding
Selection of drug heart E308 (0Cr20Ni10) wire; Φ1.2 / 1.4
Dissimilar steel welding choice heart E309 (0Cr23Ni13) wire;
Protective gas: ≥99.8% CO2
Welder: DC reverse, Panasonic 500KR / 500FR and other CO2 / MAG arc welding machine;
Submerged arc welding
Use solid ER308 (0Cr20Ni10) wire; Φ4.0
Flux: Sintered Flux: SJ601
Welder: DC reverse, Tangshan Kaiyuan ZD5-1000B submerged arc welding machine;
- To prevent the thermal cracking of welded joints:
Due to the larger tensile stress during welding, it is easy to produce solidified cracks and crater cracks. Austenitic stainless steel is easy to form columnar weld with strong directivity, resulting in the segregation of harmful impurities and the formation of intercrystalline liquid interlayers. The formation of weld hot cracks Crater and crater.
- Welding process points:
1) Due to poor thermal conductivity and large coefficient of linear expansion (3 times larger than steel), the welding is easy to produce large welding deformation under free state, and large residual stress occurs when the restraint is large. To this end, should be used to control the amount of heat input welding process and welding techniques (such as: pulse TIG welding, pulsed MIG high speed welding, etc.).
2) Try to use small current, thin diameter of the electrode and wire, pool volume as small as possible. Avoid swinging welding, multi-layer multi-track welding as much as possible to reduce the temperature between 450-850 ℃ residence time and improve corrosion resistance.
3) MIG / MAG welding using pulse arc, to avoid and reduce welding spatter.
4) The use of decentralized, segmented retreat and other reasonable welding sequence; weld joints as far as possible staggered arrangement to reduce stress concentration.
5) thick plate welding, the interlayer temperature control at 200 ℃ below, if necessary, take water-cooled way to reduce the temperature between the layers.
6) The weld facing the corrosive medium should be applied as far as possible.
7) Single-sided welding of double-sided welding, argon protection to protect the back or add ceramic liner, to prevent oxidation of the back of the weld.