Duplex stainless steel chemical tanker application
S31803/S32205 duplex stainless steel is a kind of steel with high strength, good corrosion resistance, especially pitting resistance, which can carry a variety of corrosive liquids. Therefore, the steel is widely used in the construction of chemical tankers, and has the advantages of excellent corrosion resistance, long service life and high overall cost performance. Since the surface of the stainless steel should be protected from damage during the use (it is easy to preferentially pitting) and the riveting is easily minimized (prone to crevice corrosion), the welding material with good processability and high efficiency is the first choice for chemical production. Although the traditional shipbuilding industry is currently in a downturn, the duplex stainless steel chemical tanker has grown against the trend as a high value-added ship. In order to grasp the adjustment of the shipbuilding industry, Tiantai has provided a complete solution for chemical ship welding. This paper mainly introduces the high efficiency submerged arc welding product TFS-330/TW-2209, which has been used in many chemical tankers. Manufacturing.
Duplex stainless steel chemical tanker
As a neutral flux, TFS-330 does not cause burning or increase of alloying elements such as Si and Mn. At the same time, the flux has good slag removal property and the weld bead is straight and beautiful. The particle size distribution of flux is in accordance with DINEN760:2-20, especially suitable for welding of 347 and 2209. It is widely used in the production of chemical tankers, petrochemicals and offshore platforms. When used with TW-2209, TFS-330 is excellent in corrosion resistance and mechanical properties in addition to good processability. Taking the official PQR of the chemical tanker customer as an example, welding 16mm stainless steel plates, one on each side, can ensure the weld fills up, and the efficiency is greatly improved. The test standard is based on ABS ship gauge (stretching, bending, hardness) and ASTM A923 (iron Body, gold image organization, impact, pitting), all tests meet the standard requirements. Focus on the ASTM A923 method test results as follows:
The ferrite content is 43-55%, meeting the 35-65% standard requirements. The impact value of the weld zone and the heat affected zone at -40 °C is above 80J.
The pitting rate is 2.3mdd, which is lower than the standard value ≤10mdd.
The typical gold image structure in the weld zone and heat affected zone is as follows, the organization is uniform, and there is no harmful phase structure.
Heat affected zone
In summary, TFS-330/TW-2209 has good performance and high cost performance. As a domestic brand of duplex stainless steel submerged arc welding consumables, it has been sold to customers in many industries, breaking the monopoly of imported welding consumables on S32205 stainless steel welding. At the same time, it has increased the added value of domestic brand welding consumables. In the big environment of domestic industrial transformation and upgrading, ITW Welding Group believes that the promotion of TFS-330/TW-2209 will be smoother through the continuous improvement of high value-added welding consumable products.