High-strength stainless steel rotor and method for preparing the same

A method for preparing a high-strength stainless steel rotor, the high-strength stainless steel rotor comprising the following element components by mass percentage:

• C:
• 0.03-0.050%, Cr:
• 14.90-15.80%, Ni:
• 5.00-5.70%, Cu:
• 2.20-2.80%, (Nb+Ta):
• 0.35-0.44%, Mo:
• 0.45-0.54%, V:
• 0.06-0.10%, Si:
• 0.20-0.60%, Mn:
• 0.40-0.80%, P≤0.010%, S≤0.010%, O≤0.003%, and the balance of iron and inevitable impurities, and the method comprising the following steps:
• step 1:
• preparing a rotor stainless steel billet;
• step 2:
• subjecting the rotor stainless steel billet to a first heating and a free forging, and then a first annealing and a surface treatment to obtain a forged billet;
• step 3:
• subjecting the forged billet to a second heating, a die forging, and then a second annealing and a solution treatment to obtain a forging;
• and
• step 4:
• subjecting the forging to a rough machining, an aging treatment and a finish machining to obtain the high-strength stainless steel rotor,
• wherein the die forging is conducted by pressing deformation on the forging billet with a lower die for 5 times, and the 5 times of pressing deformation are conducted as follows:
• a first pressing deformation is conducted by pressing the forged billet using an upper die with a pressure of 2,000-3,000 tons;
• a second pressing deformation and a third pressing deformation are conducted by pressing the forged billet using the upper die with a pressure of not less than 5,000 tons;
• a fourth pressing deformation is conducted by pressing the forged billet with a pressure of 4,500 tons;
• and
• a fifth pressing deformation is conducted by pressing the forged billet with a pressure of 4,000 tons for 30-40 s.