Search

CN-119876784-B - 135Ksi steel grade hydrogen sulfide corrosion resistant steel for drill, production method thereof, produced steel pipe, heat treatment method of steel pipe and application

CN119876784BCN 119876784 BCN119876784 BCN 119876784BCN-119876784-B

Abstract

The invention provides 135ksi steel grade hydrogen sulfide corrosion resistant drill steel, a production method thereof, a produced steel pipe, a heat treatment method of the steel pipe and application thereof, and the balance of Cr：0.90～1.20％,Ni：0.60～0.75％,Mo：0.80～1.00％,Al：0.020～0.050％,V：0.15～0.25％,C：0.22～0.27％,Si：0.15～0.30％,Mn：0.60～0.75％,P≤0.010％,S≤0.0015％, Fe and other unavoidable impurities. Compared with the prior art, the invention adopts a reasonable component system, a refining control technology of pure steel and a high-uniformity heat treatment process to match, so that the material has good toughness and excellent hydrogen sulfide corrosion resistance, and the produced steel pipe can be used in a deep well of ten thousand meters.

Inventors

  • CHEN ENXIN
  • WU LIN
  • YANG ZHIQIANG
  • ZHUANG ZHEN
  • WANG KAIZHONG
  • ZHANG QIAOYING
  • YIN DEFU
  • JIN GUOZHONG
  • CHEN SHIJIE
  • HU CHAOJUN

Assignees

  • 马鞍山钢铁股份有限公司

Dates

Publication Date
20260508
Application Date
20250109

Claims (12)

  1. 1. The 135ksi steel grade hydrogen sulfide corrosion resistant drill steel is characterized by comprising the following components in percentage by mass: Cr：0.90-1.20%,Ni：0.60-0.75%,Mo：0.80-1.00%,Al：0.020-0.050%, V：0.15-0.25%,C：0.22-0.27%,Si：0.15-0.30%,Mn：0.60-0.75%,P≤0.010%,S≤0.0015%, The balance of Fe and other unavoidable impurities; The 135ksi steel grade hydrogen sulfide corrosion resistant steel for drilling also comprises the following components of T= -2 x% Si+1.0 x% Mn+1.3 x% Mo+2.5 x% Ni+1.8 x% V not less than 3.10%; R=-5×(%Si+%Mn)+12×%Mo+10×%Cr+18×%V≥19.00%; The 135ksi steel grade hydrogen sulfide corrosion resistant drill adopts steel for producing a steel pipe, the low-angle grain boundary proportion of the steel pipe is more than or equal to 30%, the austenite grain size is more than or equal to 8.5 grade, the A, B, C, D nonmetallic inclusion in the steel is not more than 1.0 grade, and the total sum of A, B, C, D nonmetallic inclusions is not more than 2.5 grade; The grain size at the position of 1/2 wall thickness of the cross section of the end part of the steel pipe is less than or equal to 20 mu m, and the structure is a tempered sorbite structure; the tensile strength of the steel pipe is more than or equal to 1030MPa, the yield strength is more than or equal to 931MPa, the impact energy at-20 ℃ is more than or equal to 100J, and the elongation is more than or equal to 16%.
  2. 2. A method for producing 135ksi grade steel grade hydrogen sulfide corrosion resistant drill steel of claim 1, comprising the following steps: molten iron pretreatment, converter smelting, LF furnace refining, RH vacuum degassing, continuous casting and rolling.
  3. 3. The method according to claim 2, wherein the effective calcium sulfur ratio Ca/S formula for the calcium treatment in the RH vacuum degassing is: Ca/S= [ T.Ca- (0.31+0.02×T.Ca) × (0.99×T.O-5.44) ]/1.25× T.S, ca/S ranging from 0.8 to 2.0, wherein T.S is total sulfur mass fraction in steel, 10 -6 , T.Ca is total calcium mass fraction in steel, 10 -6 , T.O is total oxygen mass fraction in steel, 10 -6 .
  4. 4. The method according to claim 2, wherein the continuous casting, the billet diameter D and the drawing speed v are d=1029-1980×v-1470×v 2 , the unit of the billet diameter D is mm, and the unit of the drawing speed v is m/min.
  5. 5. The method according to claim 2, wherein the rolling is carried out by feeding a casting blank into a step-type heating furnace, wherein the diameter D of the casting blank and the heating time t are consistent with D=180+0.42t, the starting rolling temperature is equal to or higher than 1180 ℃, the unit of the diameter D of the casting blank is mm, and the unit of the heating time t is min.
  6. 6. A heat treatment method for a steel pipe, which is characterized in that the 135ksi steel grade hydrogen sulfide corrosion resistant drill according to claim 1 is adopted for heat treatment of the steel pipe produced by steel, and the heat treatment method comprises normalizing, quenching and tempering.
  7. 7. The heat treatment method according to claim 6, wherein the normalizing and heating temperature is 900-930 ℃, the heat preservation time t1 is determined by the wall thickness S of the steel pipe, t1=3.5×S, and the heat preservation is performed by air cooling after heat preservation, wherein the unit of the heat preservation time t1 is min, and the unit of the wall thickness S of the steel pipe is mm.
  8. 8. The heat treatment method according to claim 6, wherein the quenching and heating temperatures are 900-930 ℃, the heat preservation time t2 is determined by the wall thickness S of the steel pipe, t2=3.2×S, and water cooling is performed after heat preservation, wherein the heat preservation time t2 is in min, and the wall thickness S of the steel pipe is in mm.
  9. 9. The heat treatment method according to claim 6, wherein the tempering is performed at a tempering temperature of 670-710 ℃, the heat preservation time t3 is determined by the wall thickness S of the steel pipe, t3=6×S, and the heat preservation is performed by air cooling after heat preservation, wherein the heat preservation time t3 is in min, and the wall thickness S of the steel pipe is in mm.
  10. 10. A steel pipe produced by the heat treatment method according to any one of claims 6 to 9.
  11. 11. A steel pipe according to claim 10, wherein no fracture occurs in 720H by the american standard NACE TM0177 standard a method under load strength of 75% smys, H 2 S partial pressure of 0.1MPa, and temperature 25 ℃.
  12. 12. Use of a steel pipe according to claim 10 or 11 for deep well mining of the order of magnitude.

Description

135Ksi steel grade hydrogen sulfide corrosion resistant steel for drill, production method thereof, produced steel pipe, heat treatment method of steel pipe and application Technical Field The invention belongs to the field of alloy steel, and particularly relates to 135ksi steel grade hydrogen sulfide corrosion resistant steel for a drill, a production method thereof, a produced steel pipe, a heat treatment method of the steel pipe and application thereof. Background At present, many researches are tried to develop a 135ksi steel grade sulfur-resistant oil well pipe, but the developed 135ksi steel grade sulfur-resistant oil well pipe has difficulty in meeting the requirements of indexes on strength and toughness and simultaneously has difficulty in resisting H 2 S corrosion, and particularly, the 135ksi steel grade sulfur-resistant oil well pipe is difficult to pass through the examination of NACE TM0177 standard A solution. In addition, the oil well pipe in some researches has longer process flow and low production efficiency, so that the oil well pipe with excellent hydrogen sulfide corrosion resistance and good toughness and the preparation method thereof are required to be developed from the aspects of chemical components and process flow, and the safe and reliable use of the oil well pipe in a sulfur-containing deep well is ensured. The Chinese patent publication No. CN107177797A, published in 9 and 19 of 2017, discloses 130KSI and 135KSI grade corrosion-resistant drilling tool steel for oil and gas fields and a manufacturing method thereof, and in the disclosed technical scheme, the main principle is to increase the hardenability and toughness of the steel by adding Mn, cr, mo and other main elements, and trace V, nb, ni, cu elements are added for strengthening, and tempered sorbite tissues are obtained after primary tempering, but the low-temperature Charpy impact energy of the tempered sorbite tissues at-20 ℃ is only more than 42J, and the requirement of the drilling tool on impact toughness at the depth of ten meters cannot be met. A Chinese patent with publication number CN115927960A and publication number 2023, 4 and 7 discloses a 125Ksi steel grade hydrogen sulfide corrosion resistant oil well pipe and a preparation method thereof, wherein the technical proposal published by the patent comprises ：C:0.10％～0.20％、Si:≤0.50％、Mn:0.3％～0.8％、V:0.10％～0.20％、Mo:0.20％～0.50％,Ni:1.0％～1.5％,Cr:1.5～2.0％,Cu:1.0～2.0％、Als:≤0.05％、P:≤0.010％、S:≤0.003％, of Fe and unavoidable impurities as the rest. The main principle is that the tempered sorbite structure is obtained by adding Mn-Cr-Mo-V-Nb-Cu alloy with low carbon. But the tensile strength is more than 900MPa, the yield strength is more than 863MPa, and the strength cannot meet the requirement as the drilling and production depth is increased to more than ten thousand meters. Disclosure of Invention The invention aims to provide 135ksi steel grade hydrogen sulfide corrosion resistant steel and a production method thereof, and the steel is optimized by components and production process to obtain good toughness and excellent hydrogen sulfide corrosion resistance. The invention also aims to provide a steel pipe and a steel pipe heat treatment method, wherein the 135ksi steel grade hydrogen sulfide corrosion resistant drill is used for producing the steel pipe by adopting the steel, and the steel pipe with excellent performance is obtained by adopting a matched heat treatment process, wherein the tensile strength is not less than 1030MPa, the yield strength is not less than 931MPa, the 20 ℃ impact energy is not less than 100J, the elongation is not less than 16%, the low-angle grain boundary proportion is not less than 30%, the austenite grain size is not less than 8.5, the ABCD grade nonmetallic inclusion in the steel is not more than 1.0 grade, and the total sum is not more than 2.5 grade. The steel grade passes the hydrogen sulfide corrosion resistance test by adopting the American standard NACE TM0177 standard A method under the conditions that the loading strength is 75% SMYS, the H 2 S partial pressure is 0.1MPa and the temperature is 25 ℃, and the test is 720H without breaking. The final object of the invention is to provide a steel pipe which is produced by the heat treatment process and is used for exploitation of a deep well of ten thousand meters. The specific technical scheme of the invention is as follows: A135 ksi steel grade hydrogen sulfide corrosion resistant drill steel comprises the following components in percentage by mass: Cr：0.90～1.20％,Ni：0.60～0.75％,Mo：0.80～1.00％,Al：0.020～0.050％,V：0.15～0.25％,C：0.22～0.27％,Si：0.15～0.30％,Mn：0.60～0.75％,P≤0.010％,S≤0.0015％, The balance of Fe and other unavoidable impurities. The 135ksi steel grade hydrogen sulfide corrosion resistant drill steel also comprises the following components: The content of T.O < N > is less than or equal to 120ppm, and the content of five harmful elements Sn, sb, as, pb, bi is controlled to be