The Duplex Stainless Steel contains about 50% to 60% austenite and 50% to 40% ferrite structure after normal solution treatment (heating at 1020 ° C to 1100 ° C and water cooling). As the heating temperature increases, the two comparative examples do not change significantly.
Duplex stainless steel has good low temperature impact toughness. For example, a transverse specimen with a thickness of 20 mm can absorb more than 100 J at -80 °C. In most media, its uniform corrosion resistance and pitting resistance are good, but it should be noted that when the steel is heat treated below 950 °C, its stress corrosion resistance will deteriorate significantly due to the precipitation of σ phase. Since the ratio of the Cr equivalent to the Ni equivalent of the steel is appropriate, a large amount of primary austenite structure remains after heating at a high temperature, and the secondary austenite is formed during the cooling process, and the total austenite phase in the steel is obtained. Not less than 30% to 40% thus gives the steel a good resistance to intergranular corrosion.
In addition, as mentioned earlier, the crack tends to be low when welding such steel, without preheating and post-weld heat treatment. Since the base material contains a high N, the weld near seam area does not form a single-phase ferrite region, and the austenite content is generally not less than 30%. Suitable welding methods include tungsten argon arc welding and electrode arc welding. Generally, in order to prevent grain coarsening in the near-slit area, low-line energy welding should be used when welding. Our Duplex Stainless Steel Wire Mesh meets national standards and can be contacted if you would like more detailed information.