Efficient nickel base welding rod special for ultralow temperature steel welding of LNG (liquefied natural gas) ship

Abstract

An efficient nickel base welding rod special for ultralow temperature steel welding of an LNG (liquefied natural gas) ship comprises a nickel alloy core wire and a medicine skin wrapping the surface of the core wire; the core wire is formed by the following chemical components in percentage by weight: less than or equal to 0.03% of C, less than or equal to 0.01% of S, less than or equal to 0.01% of P, 0.5-1.5% of Mn, 4-9% of Mo, 1.5-2.5% of Nb, less than or equal to 0.25% of Si, less than or equal to 1.0% of Fe, 12-18% of Cr and the balance of Ni, and the total quantity of all components is 100%. The medicine skin comprises the following components in percentage by weight: 20-35% of marble, 2-7% of rutile, 10-25% of fluorite, 5-13% of metal chromium, 5-10% of metal manganese, 6-11% of ferro-molybdenum, 4-8% of ferrotungsten, 3-8% of ferrotitanium, 2-8% of ferrosilicon, 5.3-9% of ferroniobium and 0.5-2% of sodium carbonate, and the total quantity of all components is 100%. The welding process is good, the arc is stable and small in splattering during the welding, the deslagging after the welding is good, the formed welding seams are attractive, full-position welding is realized, the deposited metal has well mechanical properties and especially has the well comprehensive mechanical properties at the temperature of minus 196 DEG C, and the welding demands of a storage tank of a 9Nisteel LNG ship are fully met.

Description

technical field [0001] The invention relates to a nickel-based welding material, in particular to a high-efficiency nickel-based welding rod specially used for welding ultra-low temperature steel (also known as 9% Ni steel) in LNG ships. Background technique [0002] LNG (Liquefied Natural gas, liquefied natural gas) ship is a special ship used to transport liquefied natural gas. Since LNG is natural gas that has been cooled to -163°C in a liquid state, LNG ships must keep it at -163°C during transportation. Therefore, the working environment of LNG ships requires the materials used to manufacture LNG ships to have excellent low-temperature performance. [0003] 9% Ni steel has excellent toughness and high strength at extremely low temperature, and compared with austenitic stainless steel and aluminum alloy, it has low thermal expansion coefficient, good economy, and the lowest service temperature can reach -196 °C Therefore, 9% Ni steel has become one of the main materials...

AI Technical Summary

Problems solved by technology

Nowadays, 9Ni steel has been widely used in low-temperature cryogenic equipment, but at present, there are few welding materials matching 9Ni steel welding in my country, which greatly limits the development of 9Ni steel welding technology in China.

Images