Patent ID: 11873546
Assignee: POSCO CO., LTD
Field: Materials, metallurgy (Chemistry)
Classification: CPC C | IPC C

Claim 0:
1. An austenitic steel material, the austenitic steel material comprising manganese (Mn): 15 wt % to 27 wt %, carbon (C): 0.1 wt % to 1.1 wt %, phosphorus (P): more than 0 wt % and 0.03 wt % or less, aluminum (Al): 0.021 wt % to 0.050 wt %, chromium (Cr): 2.03 wt % to 5 wt %, boron (B): 0.01 wt % or less, and a balance of iron (Fe) and inevitable impurities, wherein the austenitic steel material has a composition index of sensitivity expressed by Formula 1 below within a range of 3.4 or less,

−0.451+34.131*P+111.152*Al−799.483*B+0.526*Cr≤3.4  [Formula 1]

where each of [P], [Al], [B], and [Cr] is a weight percent (wt %) of a corresponding element,
wherein the austenitic steel material has a microstructure comprising austenite in an area fraction of 95% or greater, and
wherein the austenite has an average grain size of 26 to 60 μm.