Methods for improving a toughness and a strength of a stainless steel material are described herein. For example, a high strength stainless steel material can comprise at least 11 wt. % Cr, between 0.01 wt. % and 1.0 wt. % Ni, more 0 wt. % Mo, more than 0 wt. % W, more than 0 wt. % Ti, more than 0 wt. % Nb, and more than 0 wt. % V. In some examples, the high strength stainless steel material can be heat treated with at least one quench treatment and at least one tempering heat treatment. In some examples, the high strength stainless steel material can comprise between 0.01 wt. % and 0.5 wt. % Ni, no more than 0.25 wt. % Mo, no more than 0.1 wt. % W, no more than 0.1 wt. % Ti, no more than 0.1 wt. % Nb, and no more than 0.1 wt. % V.

The stainless steel contains 0.0001 mass % or more and 0.15 mass % or less of C, 0.30 mass % or more and 2.0 mass % or less of Si, 0.1 mass % or more and 15 mass % or less of Mn, 5 mass % or more and 30 mass % or less of Ni, 0.0001 mass % or more and 0.01 mass % or less of S, 16 mass % or more and 25 mass % or less of Cr, 0 mass % or more and 5 mass % or less of Mo, 0 mass % or more and 0.005 mass % or less of Al, 0 mass % or more and 0.0010 mass % or less of Mg, 0.0010 mass % or more and 0.0060 mass % or less of O, and 0.0001 mass % or more and 0.5 mass % or less of N, and at least includes an inclusion with an equivalent circle diameter of 5 m or more, having the average composition of 5 mass % or more of MnO, 20 mass % or more of Cr.sub.2O.sub.3+Al.sub.2O.sub.3, 1 mass % or more of Al.sub.2O.sub.3, and 5 mass % or less of CaO. The number density of the inclusion having the composition is 0.5 inclusions/mm.sup.2 or less.

The invention discloses a method for preparing a stainless steel seamless tube with ultra-high cleanliness for an integrated circuit and an IC industry preparation device, and a stainless steel seamless tube with ultra-high cleanliness. The stainless steel seamless tube which comprises, by mass, C0.010%, P0.020%, S0.010%, Mn0.10%, Si0.30%, Se0.010%, Al0.010%, Cu0.20%, Cr16.50-17.00%, Ni14.50-15.00%, Mo2.20-2.50%, N0.010%, Ni0.010%, Ti0.010% and the balance Fe and impurities is prepared through a: a stainless steel refining process; b: a vacuum induction melting and vacuum consumable remelting process; c: a stainless steel forging process; d: a hot piercing process; e: a cold working process; f: an inner bore electrolytic polishing, pickling and passivation process; and g: a cleaning process. The stainless steel seamless tube with ultra-high cleanliness prepared through these processes meet the requirements for ultra-high cleanliness and high performance of 316L stainless steel tubes for a semiconductor preparation device.