High strength/corrosion-resistant austenitic stainless steel with carbon - nitrogen complex additive, and method for manufacturing same

Abstract

The present invention relates to high strength / corrosion-resistant austenitic stainless steel with a carbon-nitrogen complex additive, and particularly, to an austenitic stainless steel with a carbon (C) and nitrogen (N) complex additive containing: 8-12 wt % of manganese (Mn); 15-20 wt % of chromium (Cr); less than 2 wt % of nickel (Ni); less than 4 wt % of tungsten (W); less than 2 wt % of molybdenum (Mo); 0.6-1.0 wt % of the total content (C+N) of carbon (C) and nitrogen (N); with the remainder being iron (Fe) and other unavoidable impurities, and to a method for manufacturing same. By controlling the content of the interstitial elements (C+N, C / N) and the substitution elements (Mn+Cr, Mn / Cr, or 0.5W+Mo), the austenitic stainless steel manufactured according to the present invention has a tensile strength of more than 850 MPa and uniform elongation of more than around 45%, thereby exhibiting excellent corrosion resistance as well as improving processability, and the content of Ni, a toxic alloy element, is minimized to improve biocompatibility, making the austenite stainless steel applicable to conventional and offshore structures, desalination facilities, and materials for oil and gas facilities / drilling, transportation and the like, which require high strength and high corrosion resistance, and may also be used to manufacture various functional parts for medical prosthetic materials, and accessories such as jewelry, watches, and the like.

Description

technical field [0001] The present invention relates to a C+N austenitic stainless steel with high mechanical strength and good corrosion resistance and a manufacturing method thereof. Background technique [0002] In general, unlike carbon steel whose mechanical properties such as strength and ductility can be improved by thermomechanical treatment or phase transformation through various heat treatments, it is difficult to improve the mechanical properties of austenitic stainless steel using heat treatment methods. Thus, austenitic stainless steels rely primarily on the addition of alloying elements to improve most of their properties. [0003] Therefore, the most important technical issue in the development of new alloys is to ensure that the alloys including strength, ductility or Corrosive performs best. [0004] Most austenitic stainless steels reported in previous studies or inventions contained 16-20 wt.% chromium (Cr), 6-12 wt.% nickel (Ni), 0-2 wt.% molybdenum (Mo...

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Problems solved by technology

However, the invention disclosed by H. Berns et al. contains a relatively high content of manganese (Mn), which subsequently reduces the corrosion resistance

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