# US 11,306,368 B2 · High pressure and corrosion resistant steel and preparation method and application thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,306,368 B2 - Document ID: US11306368B2 - Status: Granted - Kind: B2 - Application number: 16/553,715 - Filed: 2019-08-28 - Published: 2020-12-17 - Granted: 2022-04-19 - Earliest claimed: 2019-06-12 - Assignees: Shanghai Qinghe Machinery Co., Ltd. - Applicants: Shanghai Qinghe Machinery CO., LTD. - Inventors: He Wang; Yang Li; Jiegao Fei; Yongliang Xin - Web page: https://patentgrep.com/patent/US11306368B2 ## CPC - C21D 8/00: Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) - C21D 6/004: {containing Cr and Ni} - C21D 6/005: {containing Mn} - C21D 6/008: {containing Si} - C22C 38/001: {containing N} - C22C 38/002: {containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60} - C22C 38/008: {containing tin} - C22C 38/02: containing silicon - C22C 38/06: containing aluminium - C22C 38/42: with copper - C22C 38/44: with molybdenum or tungsten - C22C 38/46: with vanadium - C22C 38/58: with more than 1.5% by weight of manganese - C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B) - C22C: ALLOYS (treatment of alloys C21D, C22F) ## Abstract The present invention belongs to the technical field of alloy materials, and particularly relates to high pressure and corrosion resistant steel and a preparation method and an application thereof. The high pressure and corrosion resistant steel provided by the present invention has a tensile strength of 1,020-1,100 MPa, a yield strength of 980-1,050 MPa, an elongation of 20%-22%, a reduction of area of 60%-80%, and impact energy of more than 100 J at a low temperature of 40° C., and has excellent high pressure and corrosion resistance. ## Claims ### Claim 1 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. ### Claim 2 (depends on 1) The preparation method according to claim 1, wherein the high pressure and corrosion resistant steel comprises the following components by mass percentage: 0.05%-0.12% of C, 3.37%-3.63% of Mn, 0.12%-0.27% of Si, 0.85%-1.15% of Cr, 1.35%-1.65% of Ni, 0.35%-0.45% of Mo, 0.27%-0.34% of V, 0.87%-1.19% of Cu, 0.018%-0.043% of Al, ≤0.0008% of S, ≤0.009% of P, 0.001%-0.009% of Sn, 0.0001%-0.007% of Sb, ≤0.008% of As, 0.0001%-0.008% of Pb, ≤1.2 ppm of H, ≤25 ppm of O, ≤67 ppm of N, and the balance being Fe. ### Claim 3 (depends on 1) The preparation method according to claim 1, wherein in step (1), the smelting comprises sequential fusion, refining and degassing. ### Claim 4 (depends on 2) The preparation method according to claim 2, wherein in step (1), the smelting comprises sequential fusion, refining and degassing. ### Claim 5 (depends on 1) The preparation method according to claim 1, wherein in step (2), a hot-forging temperature is 850-1,200° C., and a deformation is 45%-55%. ### Claim 6 (depends on 2) The preparation method according to claim 2, wherein in step (2), a hot-forging temperature is 850-1,200° C., and a deformation is 45%-55%. ### Claim 7 (depends on 1) The preparation method according to claim 1 wherein in step (2), a total forging ratio of hot-forging is ≥5. ### Claim 8 (depends on 2) The preparation method according to claim 2, wherein in step (2), a total forging ratio of hot-forging is ≥5. ### Claim 9 (depends on 5) The preparation method according to claim 5, wherein in step (2), a total forging ratio of hot-forging is ≥5. ### Claim 10 (depends on 6) The preparation method according to claim 6, wherein in step (2), a total forging ratio of hot-forging is ≥5. ### Claim 11 (depends on 1) The preparation method according to claim 1, wherein the method of the second stage of heat treatment is as follows: heating the forged piece treated by the first stage of heat treatment from the room temperature to 500±10° C., and carrying out first insulation; then heating to 830-850° C., carrying out second insulation, and air-cooling to the room temperature; then heating the forged piece from the room temperature to 500±10° C., and carrying out third insulation; then heating to 830-850° C., carrying out fourth insulation, and air-cooling to the room temperature; and finally heating the forged piece from the room temperature to 600±10° C., and carrying out fifth insulation; then heating to 580-620° C., carrying out sixth insulation, and oil-cooling to the room temperature. ### Claim 12 (depends on 2) The preparation method according to claim 2 wherein the method of the second stage of heat treatment is as follows: heating the forged piece treated by the first stage of heat treatment from the room temperature to 500±10° C., and carrying out first insulation; then heating to 830-850° C., carrying out second insulation, and air-cooling to the room temperature; then heating the forged piece from the room temperature to 500±10° C., and carrying out third insulation; then heating to 830-850° C., carrying out fourth insulation, and air-cooling to the room temperature; and finally heating the forged piece from the room temperature to 600±10° C., and carrying out fifth insulation; then heating to 580-620° C., carrying out sixth insulation, and oil-cooling to the room temperature. ### Claim 13 (depends on 1) The preparation method according to claim 1, wherein the method of the third stage of heat treatment is as follows: heating the forged piece treated by the second stage of heat treatment from the room temperature to 350±10° C., and carrying out I-th insulation; then heating to 580-620° C., carrying out II-th insulation, and air-cooling to the room temperature. ### Claim 14 (depends on 2) The preparation method according to claim 2, wherein the method of the third stage of heat treatment is as follows: heating the forged piece treated by the second stage of heat treatment from the room temperature to 350±10° C., and carrying out I-th insulation; then heating to 580-620° C., carrying out II-th insulation, and air-cooling to the room temperature. ### Claim 15 (depends on 11) The preparation method according to claim 11, wherein the method of the third stage of heat treatment is as follows: heating the forged piece treated by the second stage of heat treatment from the room temperature to 350±10° C., and carrying out I-th insulation; then heating to 580-620° C., carrying out II-th insulation, and air-cooling to the room temperature. ### Claim 16 (depends on 12) The preparation method according to claim 12, wherein the method of the third stage of heat treatment is as follows: heating the forged piece treated by the second stage of heat treatment from the room temperature to 350±10° C., and carrying out I-th insulation; then heating to 580-620° C., carrying out II-th insulation, and air-cooling to the room temperature.