In recent years, various types of
stainless steel materials have been used more and more in the marine environment. Most of the stainless steel materials are used well in the marine environment, but the sensitivity to stress corrosion cracking is different for different brands.
Ship thrusters: The thrusters of ships such as tugboats in the ocean can be made of 304 stainless steel, in addition to 410 stainless steel. With the development of technology, some large-scale thrusters on ocean-going ships have begun to use complex austenitic-ferritic stainless steel for casting.
Bulk Containers: Stainless steel containers are often used as bulk bag containers in shipping for liquefied natural gas (LNG), chemicals, etc. 304L stainless steel is usually used more. For containers of marine chemicals, stainless steel is mainly used for its good corrosion resistance, which is different from the storage and transportation of terrestrial chemicals. Before the container is used, the board must be carefully inspected for defects, and a thorough cleaning and passivation treatment must be performed. In fact, containers containing chemicals can be flushed with sea water, but must be flushed with fresh water immediately afterward.
Heat Exchanger: Austenitic stainless steel pipes have been widely used in coolers of forced water circulation systems and power station steam condensers. The water inlet of the latter is not suitable for copper alloy materials due to high pollution. The better material is 316 stainless steel. In coastal and harbour areas, a large number of foreign agglomerates and silt will enter the condenser pipeline, especially serious obstacles are likely to occur, and measures must be taken to eliminate this situation. In addition, unlike other non-ferrous alloys, the use of stainless steel for condenser piping is not limited by the maximum flow rate.
O-ring seals: At present, series electrical connectors and related O-ring seal positioning devices are widely produced using 304 and 316 stainless steel, especially in marine and military engineering. Satisfactory results can be obtained by using the above materials. O-ring seals can be cathodically protected through the hull, aluminum frame or other elements. If there is no cathodic protection, the fine groove of the O-ring will be unable to function due to crevice rot in a relatively short period of time.
