What's 9% Ni steel

9% Ni steel is W( Ni) -9% low carbon tool alloy quenched and also tempered steel established by the American International Nickel Company in 1944. Its framework is Martensite as well as Bainite. This steel has great durability and high toughness at extremely reduced temperature level, the thermal expansion coefficient is tiny compared to Austenitic stainless steel as well as light weight aluminum alloy, the most affordable temperature can reach a 196 ℃. The 5% Ni steel established based on 9Ni steel likewise has excellent reduced temperature level durability at the reduced temperature level of -162 ~ -196 ℃.

The main characteristics of this steel are high nickel web content, high pureness, high toughness, high reduced temperature level influence durability, great weldability. In 1952, the first 9Ni steel tank worldwide was taken into use in the United States. In 1960, the study proved that 9Ni steel without post-weld anxiety alleviation warmth therapy could be utilized safely. Ever since, 9Ni steel has turned into one of the main materials made use of in the manufacture of huge cryogenic storage tanks. The very first LNG tank built in Japan in 1969 has a maximum capacity of 20 × 104m ³.

The 9% Ni steel plate is the typically made use of 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 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 low temperature level mostly depend upon its chemical composition, specifically the components of Ni and C. On top of that, the toughness of 9Ni steel likewise depends on the pureness as well as microstructure of the steel. The 8.50 ~ 9.50 Ni web content guaranteed the hardenability to a particular degree. The decline of carbon content can significantly reduce the precipitation of carbides in toughened up martensite, thus boosting the low temperature level durability, while the high carbon material will cause significant wear and tear of welding properties and cold fragile residential properties. For that reason, in the alloying process, the web content of C ought to be strictly managed to keep it in the reduced carbon variety, and also at the exact same time, the material of P, S, Mn, Mo, Cr and also other alloying elements need to also be controlled in the low range. The material of alloying aspects and also pollutant is an essential aspect impacting the brittle transition temperature of 9Ni steel.

We understand that the liquefaction temperature of natural gas is -162 ℃, and also the volume of dissolved natural gas (LNG) is 1/600 of the aeriform state, which has higher requirements on the material of LNG tank. Currently wldsteel inc. the products used in LNG container generally are 9 Ni steel, 5 Ni, Austenitic stainless-steel, Aluminium magnesium alloy steel, and so on, as well as the most affordable temperature level can reach 9 Ni steel - 196 ℃, its high toughness, excellent reduced temperature durability, good welding efficiency, very easy to refining benefits, making it widely made use of in the manufacture of LNG tank and transport ships, is the most effective of the cryogenic environment utilizing the strength of materials.

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