摘要 |
The invention relates to a duplex ferritic austenitic stainless steel having 40 - 60 volume % ferrite and 40 - 60 volume % austenite, preferably 45 - 55 volume % ferrite and 45 - 55 volume % austenite at the annealed condition, and having improved cold workability and impact toughness. The stainless steel contains in weight % less than 0,07 % carbon (C), 0,1 - 2,0 % silicon (Si), 3 - 5 % manganese (Mn), 19 - 23 % chromium (Cr), 1,1 - 1,9 % nickel (Ni), 1,1 - 3,5 % copper (Cu), 0,18 - 0,30 % nitrogen (N), optionally molybdenum (Mo) and/or tungsten (W) in a total amount calculated with the formula (Mo + ½W) < 1,0 %, optionally 0,001 - 0,005 % boron (B), optionally up to 0,03 % of each of cerium (Ce) and/or calcium (Ca), balance being iron (Fe) and evitable impurities in such conditions for the ferrite formers and the austenite formers, i.e. for the chromium equivalent (Cr |