High pressure and corrosion resistant steel and preparation method and application thereof

A preparation method of a high pressure and corrosion resistant steel, comprising the following steps:

• (1) sequentially smelting and casting raw materials corresponding to the respective components in the high pressure and corrosion resistant steel to obtain a steel ingot;
• (2) hot-forging the steel ingot to obtain a forged piece;
• and
• (3) heat-treating the forged piece to obtain the high pressure and corrosion resistant steel;
• wherein the high pressure and corrosion resistant steel comprises the following components by mass percentage:
• 0.05%-0.15% of C, 3.35%-3.65% of Mn, 0.10%-0.28% of Si, 0.8%-1.20% of Cr, 1.35%-1,65% of Ni, 0.35%-0.45% of Mo, 0.25%-0.35% of V, 0.85%-1.20% of Cu, 0.015%-0.045% of Al, <0.001% of S, <0.010% of P, <0,010% of Sn, <0.008% of Sb, <0.010% of As, <0.0 08% of Pb, <1.5 ppm of H, <30 ppm of O, <70 ppm of N, and the balance being Fe, wherein the high pressure and corrosion resistant steel is resistant to a pressure of 80 140 MPa, wherein in step (3), the heat treatment comprises a first stage of heat treatment, a second stage of heat treatment and a third stage of heat treatment;
• the method of the first stage of heat treatment comprises:
• heating the forged piece to 550±15° C., and waiting for insulation;
• heating the to-be-insulated forged piece to 650±15° C., and carrying out 1st insulation:
• after the 1st insulation, furnace-cooling the forged piece to 300±15° C., and carrying out 2nd insulation, after the 2nd insulation, heating the forged piece to 450±15° C., and carrying out 3rd insulation, after the 3rd insulation, heating the forged piece to 750±15° C., and carrying out 4th insulation:
• after the 4th insulation, air-cooling the forged piece to <300° C., and carrying out 5th insulation, after the 5th insulation, heating the forged piece to 450 4±15° C. and carrying out 6th insulation:
• after the 6th insulation, heating the forged piece to 750±1.5′C, and carrying out 7th insulation, after the 7th insulation, furnace-cooling the forged piece to 280+1.5° C., and carrying out 8th insulation:
• after the 8th insulation, heating the forged piece to 680+15° C., and carrying out 9th insulation;
• and after the 9th insulation, furnace-cooling the forged piece to <=65° C., and air-cooling to a room temperature.