METHOD OF IMPROVING IRON-NICKEL-CHROMIUM-MANGANESE ALLOY FOR WATCH APPLICATIONS Russian patent published in 2020 - IPC C22C38/44 G04B17/06 C21D9/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to a method of producing iron-nickel-chromium-manganese alloy intended for making watches. Method of producing iron-nickel-chromium-manganese alloy intended for making watches contains the following, wt %: nickel—from 4.0 to 13.0, chromium—from 4.0 to 12.0, manganese—from 21.0 to 25.0, molybdenum—from 0 to 5.0 and/or copper—from 0 to 5.0 and iron—balance, wherein method includes provision of preliminary alloys, which are nitrided low-carbon ferrochromium containing 65 % chromium, 3 % nitrogen, the rest is iron, high-carbon ferromanganese, containing 75 % manganese, 7 % carbon, the rest is iron, and low-carbon ferromanganese, containing 95 % of manganese, the rest is iron, melting of iron, nickel and chromium in vacuum-induction furnace at nitrogen partial pressure, adding said low-carbon ferromanganese and said high-carbon ferromanganese into molten metal, controlling and maintaining alloy temperature at least 20 °C above liquidus temperature, addition of said nitrated low-carbon ferrochromium, adjustment and maintenance of alloy temperature at least 20 °C above liquidus temperature, casting of alloy. Low-carbon ferromanganese, high carbon ferromanganese and nitrided low-carbon ferrochrome are added in such quantities that said alloy contains 0.10 to 1.20 wt % carbon and/or 0.10 to 1.20 wt % nitrogen.

EFFECT: alloy is characterized by high strength.

10 cl