9% Ni steel is W( Ni) -9% low carbon tool alloy quenched and also tempered steel developed by the American International Nickel Company in 1944. Its structure is Martensite as well as Bainite. This steel has good strength as well as high stamina at extremely low temperature level, the thermal growth coefficient is little compared with Austenitic stainless steel as well as light weight aluminum alloy, the most affordable temperature can reach a 196 ℃. The 5% Ni steel developed based on 9Ni steel additionally has excellent reduced temperature level sturdiness at the low temperature level of -162 ~ -196 ℃.
The main characteristics of this steel are high nickel web content, high purity, high stamina, high wldsteel.com reduced temperature level effect durability, great weldability. In 1952, the first 9Ni steel storage tank worldwide was put into use in the United States. In 1960, the research study verified that 9Ni steel without post-weld stress and anxiety relief heat treatment might be utilized safely. Ever since, 9Ni steel has turned into one of the main products made use of in the manufacture of big cryogenic tank. The very first LNG tank built in Japan in 1969 has a maximum ability of 20 × 104m ³.
The 9% Ni steel plate is the typically used shape for this steel, as well as the steel plate have some requirements worldwide such as ASME: SA-353, EN 10028, JIS G3127, GB 24510 and also others.
EN 10028-4: X8Ni9+ NT640/ X8Ni9+ QT680.
JIS G3127: SL9N520/SL9N590.
ASME: SA-353/ SA-553-1.
GB 24510: 9Ni490/ 9Ni590A.
The mechanical properties of 9Ni steel at reduced temperature level generally depend on its chemical make-up, particularly the contents of Ni and also C. Furthermore, the sturdiness of 9Ni steel also relies on the purity as well as microstructure of the steel. The 8.50 ~ 9.50 Ni material made certain the hardenability to a particular degree. The decrease of carbon web content can greatly lower the rainfall of carbides in toughened up martensite, hence improving the reduced temperature durability, while the high carbon content will certainly cause severe degeneration of welding homes and also cool breakable residential or commercial properties. Therefore, in the alloying procedure, the material of C need to be purely managed to maintain it in the reduced carbon variety, and also at the same time, the material of P, S, Mn, Mo, Cr and also various other alloying elements should also be controlled in the reduced range. The web content of alloying aspects and also pollutant is an essential element influencing the brittle change temperature level of 9Ni steel.
We understand that the liquefaction temperature level of natural gas is -162 ℃, as well as the quantity of dissolved gas (LNG) is 1/600 of the aeriform state, which has greater demands on the material of LNG storage tank. Currently the materials utilized in LNG container generally are 9 Ni steel, 5 Ni, Austenitic stainless-steel, Aluminium magnesium alloy steel, etc., as well as the lowest temperature level can reach 9 Ni steel – 196 ℃, its high stamina, outstanding reduced temperature toughness, great welding efficiency, very easy to processing benefits, making it commonly used in the manufacture of LNG tank and transportation ships, is the most effective of the cryogenic atmosphere utilizing the strength of materials.