Abstract: A high-Si content austenitic stainless steel, which exhibits stable acid resistance and excellent corrosion resistance in high-temperature and concentrated nitric acid, has a chemical composition comprising: C: at most 0.04%; Si: 2.5-7.0%; Mn: at most 10%; P at most 0.03%; S: at most 0.03%; N: at most 0.035%; sol. Al: at most 0.03%; Cr: 7-20%; Ni: 10-22%; optionally, one or more types selected from Nb, Ti, Ta and Zr: 0.05-0.7% in total; and the remainder being Fe and impurities, wherein a total amount of B1 type inclusions measured by a method according to JIS G0555 (2003) Annex 1 “Microscopic Testing for the Non-Metallic Inclusions on the Point Counting Principle” is not more than 0.03% by area %.

Abstract: A high-Si content austenitic stainless steel, which exhibits stable acid resistance and excellent corrosion resistance in high-temperature and concentrated nitric acid, has a chemical composition comprising: C: at most 0.04%; Si: 2.5-7.0%; Mn: at most 10%; P at most 0.03%; S: at most 0.03%; N: at most 0.035%; sol. Al: at most 0.03%; Cr: 7-20%; Ni: 10-22%; optionally, one or more types selected from Nb, Ti, Ta and Zr: 0.05-0.7% in total; and the remainder being Fe and impurities, wherein a total amount of B1 type inclusions measured by a method according to JIS G0555 (2003) Annex 1 “Microscopic Testing for the Non-Metallic Inclusions on the Point Counting Principle” is not more than 0.03% by area %.

Abstract: A high Si-containing austenitic stainless steel having corrosion resistance in a nitric acid environment at a high temperature is made by hot-rolling a slab of stainless steel and heat treating the hot-rolled stainless steel at a temperature of 1100 to 1160° C. The steel is cooled at cooling rate of at least 100° C./min. The stainless steel has a chemical composition containing: C: at most 0.04%; Cr: 7 to 20%, Ni: 10 to 22%, Si: 2.5 to 7%, Mn: at most 10%, sol. Al: at most 0.03%, P: at most 0.03%, S: at most 0.03%; N: at most 0.035%, a total of one or more of Nb, Ti, Ta, and Zr being 0.05 to 0.7%; and the remainder Fe and impurities. The heating temperature during the hot rolling is Th in which ?T of Formula (1): Th=1135?90Si?2.9Cr+40 Ni??T is at least 30?C.