9Ni steel low hydrogen type nickel-based welding electrode for welding LNG ship

Abstract

A 9Ni steel low hydrogen type nickel-based welding electrode for welding an LNG ship comprises a pure nickel core wire and a coating covered on the surface of the core wire. Ingredients and contents (wt %) of the core wire are as follows: no more that 0.02% of C, no more than 0.01% of S, no more than 0.01% of P, no less than 99.0% of Ni, the rest element content no more than 0.50%, and all the ingredients total 100%. Powder ingredients of the coating comprise, by weight, marble 25-35%, fluorite 10-21%, chromium metal 12-28%, manganese metal 4-10%, ferromolybdenum 8-16%, ferrotungsten 1-6%, ferrocolumbium 7-15%, organic matter 0-2%, sodium carbonate 0-2%, and all the ingredients total 100%. According to the proportion, all the ingredients of the powder are evenly mixed with sodium silicate which accounts for 25-35% of the total mass, and then are sent into a press coater and covered on the core wire, and finished after a low temperature baking and a high temperature baking. The 9Ni steel low hydrogen type nickel-based welding electrode for welding the LNG ship has a good welding manufacturability and can be welded from all the positions, the deposited metals have the advantages of high yield strength, high tensile strength and good low temperature impact toughness, and even have a high low temperature impact value in -196oC.

Description

technical field [0001] The invention relates to a nickel-based welding material, in particular to a low-hydrogen nickel-based welding electrode suitable for welding 9Ni steel (also known as 9%Ni steel) for LNG ships. Background technique [0002] 9Ni steel is a W steel developed by the American International Nickel Company in 1944. (Ni) -9% medium alloy steel, which is a low carbon quenched and tempered steel. This kind of steel has good toughness and high strength at extremely low temperature, and compared with austenitic stainless steel and aluminum alloy, it has the advantages of small thermal expansion coefficient and good economy, and the service temperature can reach as low as -196°C. The main characteristics of 9Ni steel are high nickel content, high purity, high strength, high low temperature impact toughness, and good weldability. Its chemical composition is: Ni: 8.5-9.5%, C: 0.0005-0.012%, Si: 0.05 ~0.4%, Mn: 0.30~0.80%, S≤0.005%, P≤0.008%, Mo: 0.05~0.013%, V≤0.0...

AI Technical Summary

Problems solved by technology

[0004] With the adjustment of my country's energy strategy, the LNG industry has maintained a momentum of rapid development in my country. The development of the LNG industry has greatly increased the demand for 9Ni steel and its welding materials, but currently there are few welding materials that match the welding of 9Ni steel. , which greatly limits the development of 9Ni steel welding technology in China

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