Corrosion-resistant steel strip and preparation method thereof

Abstract

The present invention discloses a method for preparing a corrosion-resistant steel strip, comprising the following steps: (1) ball-milling niobium carbide powder, sieving the sieved powder, degreasing the sieved powder, and immersing the sieved powder in a chemical plating solution to obtain a plating powder; (2) subjecting the plating powder to a plasma glow nitriding furnace for glow plasma treatment to obtain a plasma-treated powder; (3) uniformly mixing carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder, and Fe-Al alloy powder to obtain a mixed alloy powder, melting the mixed powder into a melt, stirring, desulfurizing, deoxidizing, and skimming the slag, then adding the plasma-treated powder, stirring, and immediately pouring the mixture into a mold for casting to obtain a cast plate; and (4) performing a constant temperature homogenization treatment, rough rolling, and finish rolling to obtain a corrosion-resistant steel strip. The steel strip prepared by the method of the present invention has good mechanical strength and corrosion resistance, is suitable for working in an environment with a certain corrosive medium or an environment with high stress requirements, improves the durability of steel components, and reduces maintenance costs.

Description

Technical Field

[0001] The present invention relates to the technical field of steel strip manufacturing, and in particular to a corrosion-resistant steel strip and a preparation method thereof. Background Art

[0002] Corrosion-resistant steel is a low-alloy steel that lies between ordinary steel and stainless steel. By adding a small amount of alloying elements to the steel, a dense, protective rust layer forms on the surface of the steel material in the working environment. This prevents corrosive media from penetrating into the steel matrix, slowing the spread of rust deep into the steel material, thereby improving corrosion resistance. Currently, most corrosion-resistant steels are coated with anti-rust paint or plating. However, the surface plating or anti-rust layer is prone to cracking when the steel strip is bent under stress or scratched. Corrosive media can easily penetrate the steel strip through these cracks, causing material damage. Summary of the Invention

[0003] To this end, the present invention provides a method for preparing a corrosion-resistant steel strip, comprising the following steps:

[0004] (1) preparing a chemical plating solution, wherein the components of the chemical plating solution are nickel sulfate, sodium hypophosphite, ammonium acetate, trisodium citrate, cerium dioxide powder, glycine, thiourea, sodium lauryl sulfate and water; grinding niobium carbide powder by ball milling, sieving after ball milling to obtain sieved powder, soaking the sieved powder in acetone, stirring for more than 20 minutes under an ultrasonic environment, and then separating the solid and liquid, drying the solid phase at 60° C. for more than 2 hours, soaking the dried solid phase in the chemical plating solution, heating to 80±5° C. in a water bath and plating at a constant temperature for more than 60 minutes, condensing and refluxing during the plating process; after the plating is completed, separating the solid and liquid, washing the solid phase with deionized water for more than 3 times, and drying at 60° C. for more than 3 hours to obtain a plating powder;

[0005] (2) placing the plated powder on a cathode disk in a plasma glow nitriding furnace, and subjecting it to glow plasma treatment in an environment of hydrogen and methane mixed gas, with a voltage of 700-750 V, a gas pressure of 400-450 Pa, and a treatment time of 6-10 h. After the treatment is completed, the powder is cooled to room temperature in a hydrogen protective atmosphere to obtain a plasma-treated powder;

[0006] (3) mixing carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder uniformly to obtain mixed alloy powder, heating the mixed powder to 1600-1620° C. to melt into a melt, stirring with bottom argon for 20-30 minutes, desulfurizing, deoxidizing, and skimming, and then adding the plasma-treated powder, continuing to stir with bottom argon for 4-5 minutes after adding the materials, and then immediately pouring the mixture into a mold for casting to obtain a cast plate;

[0007] (4) The cast slab is heated to 1200-1280° C. and subjected to constant temperature homogenization treatment for 100-120 min, and then rough-rolled into a strip at 1100-1160° C., and then subjected to 5-7 rounds of finish rolling to form the corrosion-resistant steel strip, with the final rolling temperature being above 950° C.

[0008] Furthermore, in step (1), the concentrations of the components in the chemical plating solution are: nickel sulfate 25-27 g / L, sodium hypophosphite 22-24 g / L, ammonium acetate 18-20 g / L, trisodium citrate 25-26 g / L, cerium dioxide powder 1-2 g / L, glycine 1-3 g / L, thiourea 0.4-0.5 mg / L, sodium lauryl sulfate 0.8-1 mg / L, and the solvent is water; the mass ratio of the dried solid phase immersed in the chemical plating solution is solid phase: chemical plating solution = 1:30-50.

[0009] Furthermore, in step (2), the volume ratio of hydrogen to methane in the hydrogen and methane mixed gas is hydrogen:methane=100:0.8-1.

[0010] Furthermore, in step (3), the carbon steel powder is 20# carbon steel powder; the weight percentage of Cr in the Fe-Cr alloy powder is 60wt%; the weight percentage of Mo in the Fe-Mo alloy powder is 55wt%; the weight percentage of Si in the Fe-Si alloy powder is 75wt%; the weight percentage of Al in the Fe-Al alloy powder is 50wt%; and the mixed weight ratio of carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder is carbon steel powder: Fe-Cr alloy powder: Fe-Mo alloy powder: Fe-Si alloy powder: Fe-Al alloy powder = 100: 0.7~0.8: 1~2: 0.9~1.2: 0.6~1.6.

[0011] Furthermore, in the step (3), the weight of the plasma-treated powder added is 1.2% to 1.5% of the total weight of the mixed alloy powder.

[0012] The beneficial effects of the present invention are that the steel strip prepared by the method of the present invention has good mechanical strength and corrosion resistance, is suitable for working in an environment with a certain corrosive medium or an environment with high stress requirements, improves the durability of steel components, and reduces maintenance costs. DETAILED DESCRIPTION

[0013] The present invention will be further described below with reference to the embodiments.

[0014] Example 1

[0015] A method for preparing a corrosion-resistant steel strip, comprising the following steps:

[0016] (1) preparing a chemical plating solution, wherein the components of the chemical plating solution are nickel sulfate, sodium hypophosphite, ammonium acetate, trisodium citrate, cerium dioxide powder, glycine, thiourea, sodium lauryl sulfate and water; the concentrations of the components in the chemical plating solution are: nickel sulfate 25 g / L, sodium hypophosphite 22 g / L, ammonium acetate 18 g / L, trisodium citrate 25 g / L, cerium dioxide powder 1 g / L, glycine 1 g / L, thiourea 0.4 mg / L, sodium lauryl sulfate 0.8 mg / L, and the solvent is water; ball milling the niobium carbide powder, and then grinding it for 2 minutes. 000 mesh sieve to obtain sieved powder, the sieved powder is immersed in acetone for degreasing and cleaning, stirred under ultrasonic environment for 20 minutes, and then solid-liquid separation is performed, the solid phase is dried at 60°C for 2 hours to remove acetone, and the dried solid phase is immersed in the chemical plating solution, and the mass ratio of the dried solid phase immersed in the chemical plating solution is solid phase: chemical plating solution = 1:30; heating to 80±5°C in a water bath and constant temperature plating for 60 minutes, condensing and reflux during the plating process; after the plating is completed, solid-liquid separation is performed, the solid phase is washed with deionized water 3 times, and dried at 60°C for 3 hours to obtain plating powder;

[0017] (2) placing the plated powder on a cathode disk in a plasma glow nitriding furnace and subjecting it to glow plasma treatment in an environment of a hydrogen and methane mixed gas, wherein the volume ratio of hydrogen to methane in the hydrogen and methane mixed gas is hydrogen:methane = 100:0.8; the voltage is 750 V, the pressure is 400 Pa, and the treatment time is 6 h. After the treatment is completed, the powder is cooled to room temperature in a hydrogen protective atmosphere to obtain a plasma-treated powder;

[0018] (3) Carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder are uniformly mixed to obtain a mixed alloy powder, wherein the carbon steel powder is 20# carbon steel powder; the weight percentage of Cr in the Fe-Cr alloy powder is 60wt%; the weight percentage of Mo in the Fe-Mo alloy powder is 55wt%; the weight percentage of Si in the Fe-Si alloy powder is 75wt%; the weight percentage of Al in the Fe-Al alloy powder is 50wt%; the carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder The powder and the Fe-Al alloy powder are mixed in a weight ratio of carbon steel powder: Fe-Cr alloy powder: Fe-Mo alloy powder: Fe-Si alloy powder: Fe-Al alloy powder = 100:0.7:1:0.9:0.6; the mixed powder is heated to 1610° C. and melted into a melt, bottom-blown with argon and stirred for 20 minutes, desulfurized, deoxidized, and skimmed, and then the plasma-treated powder is added, the weight of the plasma-treated powder being 1.2% of the total weight of the mixed alloy powder; after the addition, the bottom-blown with argon and stirred for 4 minutes, and then immediately poured into a mold for casting to obtain a cast slab (50 mm thick);

[0019] (4) The ingot plate is heated to 1250°C and subjected to constant temperature homogenization treatment for 100 minutes, and then rough-rolled into a strip at 1140°C, and then subjected to 6 rounds of finish rolling to form the corrosion-resistant steel strip (with a thickness of 5 mm), with the final rolling temperature being 960°C.

[0020] Example 2

[0021] A method for preparing a corrosion-resistant steel strip, comprising the following steps:

[0022] (1) preparing a chemical plating solution, wherein the components of the chemical plating solution are nickel sulfate, sodium hypophosphite, ammonium acetate, trisodium citrate, cerium dioxide powder, glycine, thiourea, sodium lauryl sulfate and water; the concentrations of the components in the chemical plating solution are: nickel sulfate 26 g / L, sodium hypophosphite 23 g / L, ammonium acetate 19 g / L, trisodium citrate 25 g / L, cerium dioxide powder 1 g / L, glycine 2 g / L, thiourea 0.4 mg / L, sodium lauryl sulfate 0.9 mg / L, and the solvent is water; ball milling the niobium carbide powder, and then grinding it for 2 minutes. 000 mesh sieve to obtain sieved powder, the sieved powder is immersed in acetone for degreasing and cleaning, stirred under ultrasonic environment for 20 minutes, and then solid-liquid separation is performed, the solid phase is dried at 60°C for 2 hours to remove acetone, and the dried solid phase is immersed in the chemical plating solution, and the mass ratio of the dried solid phase immersed in the chemical plating solution is solid phase: chemical plating solution = 1:30; heating to 80±5°C in a water bath and constant temperature plating for 60 minutes, condensing and reflux during the plating process; after the plating is completed, solid-liquid separation is performed, the solid phase is washed with deionized water 3 times, and dried at 60°C for 3 hours to obtain plating powder;

[0023] (2) placing the plated powder on a cathode disk in a plasma glow nitriding furnace and subjecting it to glow plasma treatment in an environment of a hydrogen and methane mixed gas, wherein the volume ratio of hydrogen to methane in the hydrogen and methane mixed gas is hydrogen:methane=100:0.9; the voltage is 750V, the pressure is 400Pa, and the treatment time is 8h. After the treatment is completed, the powder is cooled to room temperature in a hydrogen protective atmosphere with the furnace to obtain a plasma-treated powder;

[0024] (3) Carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder are uniformly mixed to obtain a mixed alloy powder, wherein the carbon steel powder is 20# carbon steel powder; the weight percentage of Cr in the Fe-Cr alloy powder is 60wt%; the weight percentage of Mo in the Fe-Mo alloy powder is 55wt%; the weight percentage of Si in the Fe-Si alloy powder is 75wt%; the weight percentage of Al in the Fe-Al alloy powder is 50wt%; the carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder, The powder and the Fe-Al alloy powder are mixed in a weight ratio of carbon steel powder: Fe-Cr alloy powder: Fe-Mo alloy powder: Fe-Si alloy powder: Fe-Al alloy powder = 100:0.7:1:1:0.8; the mixed powder is heated to 1610° C. and melted into a melt, bottom-blown with argon and stirred for 20 minutes, desulfurized, deoxidized, and skimmed, and then the plasma-treated powder is added, with the weight of the plasma-treated powder being 1.3% of the total weight of the mixed alloy powder; after the addition, bottom-blown with argon and stirred for 4 minutes, and then immediately poured into a mold for casting to obtain a cast slab (50 mm thick);

[0025] (4) The ingot plate is heated to 1250°C and subjected to constant temperature homogenization treatment for 100 minutes, and then rough-rolled into a strip at 1140°C, and then subjected to 6 rounds of finish rolling to form the corrosion-resistant steel strip (with a thickness of 5 mm), with the final rolling temperature being 960°C.

[0026] Example 3

[0027] A method for preparing a corrosion-resistant steel strip, comprising the following steps:

[0028] (1) preparing a chemical plating solution, wherein the components of the chemical plating solution are nickel sulfate, sodium hypophosphite, ammonium acetate, trisodium citrate, cerium dioxide powder, glycine, thiourea, sodium lauryl sulfate and water; the concentrations of the components in the chemical plating solution are: nickel sulfate 26 g / L, sodium hypophosphite 23 g / L, ammonium acetate 19 g / L, trisodium citrate 26 g / L, cerium dioxide powder 2 g / L, glycine 2 g / L, thiourea 0.5 mg / L, sodium lauryl sulfate 0.9 mg / L, and the solvent is water; ball milling the niobium carbide powder, and then grinding it for 2 minutes. 000 mesh sieve to obtain sieved powder, the sieved powder is immersed in acetone for degreasing and cleaning, stirred under ultrasonic environment for 20 minutes, and then solid-liquid separation is performed, the solid phase is dried at 60°C for 2 hours to remove acetone, and the dried solid phase is immersed in the chemical plating solution, and the mass ratio of the dried solid phase immersed in the chemical plating solution is solid phase: chemical plating solution = 1:30; heating to 80±5°C in a water bath and constant temperature plating for 60 minutes, condensing and reflux during the plating process; after the plating is completed, solid-liquid separation is performed, the solid phase is washed with deionized water 3 times, and dried at 60°C for 3 hours to obtain plating powder;

[0029] (2) placing the plated powder on a cathode disk in a plasma glow nitriding furnace and subjecting it to glow plasma treatment in an environment of a hydrogen and methane mixed gas, wherein the volume ratio of hydrogen to methane in the hydrogen and methane mixed gas is hydrogen:methane=100:0.9; the voltage is 750V, the pressure is 400Pa, and the treatment time is 8h. After the treatment is completed, the powder is cooled to room temperature in a hydrogen protective atmosphere with the furnace to obtain a plasma-treated powder;

[0030] (3) Carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder are uniformly mixed to obtain a mixed alloy powder, wherein the carbon steel powder is 20# carbon steel powder; the weight percentage of Cr in the Fe-Cr alloy powder is 60wt%; the weight percentage of Mo in the Fe-Mo alloy powder is 55wt%; the weight percentage of Si in the Fe-Si alloy powder is 75wt%; the weight percentage of Al in the Fe-Al alloy powder is 50wt%; the carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder, The powder and the Fe-Al alloy powder are mixed in a weight ratio of carbon steel powder: Fe-Cr alloy powder: Fe-Mo alloy powder: Fe-Si alloy powder: Fe-Al alloy powder = 100:0.8:2:1:1.2; the mixed powder is heated to 1610° C. and melted into a melt, bottom-blown with argon and stirred for 20 minutes, desulfurized, deoxidized, and skimmed, and then the plasma-treated powder is added, with the weight of the plasma-treated powder being 1.4% of the total weight of the mixed alloy powder; after the addition, bottom-blown with argon and stirred for 4 minutes, and then immediately poured into a mold for casting to obtain a cast plate (50 mm thick);

[0031] (4) The ingot plate is heated to 1250°C and subjected to constant temperature homogenization treatment for 100 minutes, and then rough-rolled into a strip at 1140°C, and then subjected to 6 rounds of finish rolling to form the corrosion-resistant steel strip (with a thickness of 5 mm), with the final rolling temperature being 960°C.

[0032] Example 4

[0033] A method for preparing a corrosion-resistant steel strip, comprising the following steps:

[0034] (1) preparing a chemical plating solution, wherein the components of the chemical plating solution are nickel sulfate, sodium hypophosphite, ammonium acetate, trisodium citrate, cerium dioxide powder, glycine, thiourea, sodium lauryl sulfate and water; the concentrations of the components in the chemical plating solution are: nickel sulfate 27 g / L, sodium hypophosphite 24 g / L, ammonium acetate 20 g / L, trisodium citrate 26 g / L, cerium dioxide powder 2 g / L, glycine 3 g / L, thiourea 0.5 mg / L, sodium lauryl sulfate 1 mg / L, and the solvent is water; ball milling the niobium carbide powder, and grinding it for 20 minutes after ball milling. 00 mesh sieve to obtain sieved powder, the sieved powder is immersed in acetone for degreasing and cleaning, stirred under ultrasonic environment for 20 minutes, then solid-liquid separation, the solid phase is dried at 60°C for 2 hours to remove acetone, and the dried solid phase is immersed in the chemical plating solution, and the mass ratio of the dried solid phase immersed in the chemical plating solution is solid phase: chemical plating solution = 1:30; heating to 80±5°C in a water bath and constant temperature plating for 60 minutes, condensing and reflux during the plating process; after the plating is completed, solid-liquid separation is performed, the solid phase is washed with deionized water 3 times, and dried at 60°C for 3 hours to obtain plating powder;

[0035] (2) placing the plated powder on a cathode disk in a plasma glow nitriding furnace, and performing glow plasma treatment in an environment of a hydrogen and methane mixed gas, wherein the volume ratio of hydrogen to methane in the hydrogen and methane mixed gas is hydrogen:methane = 100:1; the voltage is 750V, the pressure is 400Pa, and the treatment time is 10h. After the treatment is completed, the powder is cooled to room temperature in a hydrogen protective atmosphere with the furnace to obtain a plasma-treated powder;

[0036] (3) Carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder are uniformly mixed to obtain a mixed alloy powder, wherein the carbon steel powder is 20# carbon steel powder; the weight percentage of Cr in the Fe-Cr alloy powder is 60wt%; the weight percentage of Mo in the Fe-Mo alloy powder is 55wt%; the weight percentage of Si in the Fe-Si alloy powder is 75wt%; the weight percentage of Al in the Fe-Al alloy powder is 50wt%; the carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder The powder and the Fe-Al alloy powder are mixed in a weight ratio of carbon steel powder: Fe-Cr alloy powder: Fe-Mo alloy powder: Fe-Si alloy powder: Fe-Al alloy powder = 100:0.8:2:1.2:1.6; the mixed powder is heated to 1610° C. and melted into a melt, bottom-blown with argon and stirred for 20 minutes, desulfurized, deoxidized, and skimmed, and then the plasma-treated powder is added, the weight of the plasma-treated powder being 1.5% of the total weight of the mixed alloy powder; after the addition, the bottom-blown with argon and stirred for 4 minutes, and then immediately poured into a mold for casting to obtain a cast slab (50 mm thick);

[0037] (4) The ingot plate is heated to 1250°C and subjected to constant temperature homogenization treatment for 100 minutes, and then rough-rolled into a strip at 1140°C, and then subjected to 6 rounds of finish rolling to form the corrosion-resistant steel strip (with a thickness of 5 mm), with the final rolling temperature being 960°C.

[0038] Comparative Example 1

[0039] A method for preparing a steel strip for comparison comprises the following steps:

[0040] (1) The niobium carbide powder was ball-milled and passed through a 2000-mesh sieve to obtain a sieved powder. The sieved powder was soaked in acetone for degreasing and cleaning, stirred under an ultrasonic environment for 20 minutes, and then solid-liquid separation was performed. The solid phase was dried at 60° C. for 2 hours to remove the acetone, thereby obtaining a pretreated powder of this comparative example;

[0041] (2) Carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder are uniformly mixed to obtain a mixed alloy powder, wherein the carbon steel powder is 20# carbon steel powder; the weight percentage of Cr in the Fe-Cr alloy powder is 60wt%; the weight percentage of Mo in the Fe-Mo alloy powder is 55wt%; the weight percentage of Si in the Fe-Si alloy powder is 75wt%; the weight percentage of Al in the Fe-Al alloy powder is 50wt%; the carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder are uniformly mixed to obtain a mixed alloy powder, wherein the carbon steel powder is 20# carbon steel powder; the weight percentage of Cr in the Fe-Cr alloy powder is 60wt%; the weight percentage of Mo in the Fe-Mo alloy powder is 55wt%; the weight percentage of Si in the Fe-Si alloy powder is 75wt%; the weight percentage of Al in the Fe-Al alloy powder is 50wt%; The weight ratio of the i alloy powder and the Fe-Al alloy powder is 100:0.8:2:1:1.2; the mixed powder is heated to 1610° C. and melted into a melt. The mixture is stirred with argon at the bottom for 20 minutes, desulfurized, deoxidized, and skimmed. The pretreated powder is then added, with the weight of the pretreated powder being 1.4% of the total weight of the mixed alloy powder. After the addition, the mixture is stirred with argon at the bottom for 4 minutes. The mixture is then immediately poured into a mold for casting to obtain a cast slab (50 mm thick).

[0042] (3) The cast slab was heated to 1250°C and homogenized for 100 min, and then rough-rolled into a strip at 1140°C, and then finished-rolled 6 times to obtain the corrosion-resistant steel strip (5 mm thick) described in the comparative example, with the final rolling temperature at 960°C.

[0043] Comparative Example 2

[0044] A method for preparing a steel strip for comparison comprises the following steps:

[0045] (1) The niobium carbide powder was ball-milled and passed through a 2000-mesh sieve to obtain a sieved powder. The sieved powder was soaked in acetone for degreasing and cleaning, stirred under an ultrasonic environment for 20 minutes, and then solid-liquid separation was performed. The solid phase was dried at 60° C. for 2 hours to remove the acetone, thereby obtaining a pretreated powder of this comparative example;

[0046] (2) placing the pretreated powder on a cathode disk in a plasma glow nitriding furnace and subjecting it to glow plasma treatment in an environment of a hydrogen and methane mixed gas, wherein the volume ratio of hydrogen to methane in the hydrogen and methane mixed gas is hydrogen:methane = 100:0.9; the voltage is 750 V, the pressure is 400 Pa, and the treatment time is 8 h. After the treatment is completed, the powder is cooled to room temperature in a hydrogen protective atmosphere with the furnace to obtain the plasma-treated powder of this comparative example;

[0047] (3) Carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder are uniformly mixed to obtain a mixed alloy powder, wherein the carbon steel powder is 20# carbon steel powder; the weight percentage of Cr in the Fe-Cr alloy powder is 60wt%; the weight percentage of Mo in the Fe-Mo alloy powder is 55wt%; the weight percentage of Si in the Fe-Si alloy powder is 75wt%; the weight percentage of Al in the Fe-Al alloy powder is 50wt%; the carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder, The powder and the Fe-Al alloy powder are mixed in a weight ratio of carbon steel powder: Fe-Cr alloy powder: Fe-Mo alloy powder: Fe-Si alloy powder: Fe-Al alloy powder = 100:0.8:2:1:1.2; the mixed powder is heated to 1610° C. and melted into a melt, bottom-blown with argon and stirred for 20 minutes, desulfurized, deoxidized, and skimmed, and then the plasma-treated powder is added, with the weight of the plasma-treated powder being 1.4% of the total weight of the mixed alloy powder; after the addition, bottom-blown with argon and stirred for 4 minutes, and then immediately poured into a mold for casting to obtain a cast plate (50 mm thick);

[0048] (4) The cast slab was heated to 1250°C and homogenized for 100 min, and then rough-rolled into a strip at 1140°C, and then finished-rolled 6 times to obtain the corrosion-resistant steel strip (5 mm thick) described in the comparative example, with the final rolling temperature at 960°C.

[0049] Comparative Example 3

[0050] A method for preparing a steel strip for comparison comprises the following steps:

[0051] (1) preparing a chemical plating solution, wherein the components of the chemical plating solution are nickel sulfate, sodium hypophosphite, ammonium acetate, trisodium citrate, cerium dioxide powder, glycine, thiourea, sodium lauryl sulfate and water; the concentrations of the components in the chemical plating solution are: nickel sulfate 26 g / L, sodium hypophosphite 23 g / L, ammonium acetate 19 g / L, trisodium citrate 26 g / L, cerium dioxide powder 2 g / L, glycine 2 g / L, thiourea 0.5 mg / L, sodium lauryl sulfate 0.9 mg / L, and the solvent is water; ball milling the niobium carbide powder, and then grinding it for 2 minutes. 000 mesh sieve to obtain sieved powder, the sieved powder is immersed in acetone for degreasing and cleaning, stirred under ultrasonic environment for 20 minutes, and then solid-liquid separation is performed, the solid phase is dried at 60°C for 2 hours to remove acetone, and the dried solid phase is immersed in the chemical plating solution, and the mass ratio of the dried solid phase immersed in the chemical plating solution is solid phase: chemical plating solution = 1:30; heating to 80±5°C in a water bath and constant temperature plating for 60 minutes, condensing and reflux during the plating process; after the plating is completed, solid-liquid separation is performed, the solid phase is washed with deionized water 3 times, and dried at 60°C for 3 hours to obtain plating powder;

[0052] (2) Carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder are uniformly mixed to obtain a mixed alloy powder, wherein the carbon steel powder is 20# carbon steel powder; the weight percentage of Cr in the Fe-Cr alloy powder is 60wt%; the weight percentage of Mo in the Fe-Mo alloy powder is 55wt%; the weight percentage of Si in the Fe-Si alloy powder is 75wt%; the weight percentage of Al in the Fe-Al alloy powder is 50wt%; the carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder are uniformly mixed to obtain a mixed alloy powder, wherein the carbon steel powder is 20# carbon steel powder; the weight percentage of Cr in the Fe-Cr alloy powder is 60wt%; the weight percentage of Mo in the Fe-Mo alloy powder is 55wt%; the weight percentage of Si in the Fe-Si alloy powder is 75wt%; the weight percentage of Al in the Fe-Al alloy powder is 50wt%; The Si alloy powder and the Fe-Al alloy powder were mixed in a weight ratio of carbon steel powder: Fe-Cr alloy powder: Fe-Mo alloy powder: Fe-Si alloy powder: Fe-Al alloy powder = 100:0.8:2:1:1.2; the mixed powder was heated to 1610° C. and melted into a melt. The mixture was stirred with bottom argon blowing for 20 minutes, desulfurized, deoxidized, and skimmed. The plating powder was then added, with the weight of the plating powder being 1.4% of the total weight of the mixed alloy powder. After the addition, the mixture was stirred with bottom argon blowing for 4 minutes, and then immediately poured into a mold for casting to obtain a cast plate (50 mm thick);

[0053] (3) The cast slab was heated to 1250°C and homogenized for 100 min, and then rough-rolled into a strip at 1140°C, and then finished-rolled 6 times to obtain the corrosion-resistant steel strip (5 mm thick) described in the comparative example, with the final rolling temperature at 960°C.

[0054] Example 5

[0055] In accordance with the requirements of standard GB / T 228.1-2021, the corrosion-resistant steel strips prepared by the methods described in each embodiment and comparative example were processed into tensile specimens with a thickness of 5 mm. The tensile strength of each specimen was tested on a universal testing machine at a tensile rate of 0.2 mm / min. Three samples were tested for each group of specimens, and the average value was taken as the tensile strength value of the group. The corrosion-resistant steel strips prepared by the methods described in each embodiment and comparative example were processed into small pieces of 2 cm × 2 cm × 5 mm. The small pieces were connected with wires, exposing only a 1 cm × 1 cm test surface, and the remaining surfaces were completely covered with insulating glue to make electrochemical test specimens. The electrochemical test specimens were then subjected to polarization curve testing on an electrochemical workstation. The electrolyte solution was a 3.5 wt% sodium chloride aqueous solution, a platinum electrode was the auxiliary electrode, and a saturated calomel electrode was the reference electrode. The self-corrosion potential was obtained, and the results are shown in Table 1.

[0056] As can be seen from Table 1, the steel strip prepared by the method of the present invention has good mechanical strength and corrosion resistance, is suitable for working in an environment with a certain corrosive medium or in an environment with high stress requirements, improves the durability of steel components, and reduces maintenance costs. By comparing Example 3 of the present invention and the comparative examples, it can be seen that by adding the plasma-treated powder of the present invention, the tensile strength of the steel can be effectively improved, and the positive shift of the self-corrosion potential can be promoted to a certain extent, thereby improving the corrosion resistance. This is mainly because after adding the plasma-treated powder of the present invention, the plasma-treated powder acts as a non-uniform nucleation site during the casting cooling process of the steel, thereby improving the nucleation rate of the steel, and the plasma-treated powder is pinned in the steel matrix grains as a second phase particle, which can effectively prevent dislocation movement during the deformation process, play a second phase strengthening effect, and thus improve the tensile strength. On the other hand, the coating powder forms a corrosion-resistant cerium oxide-nickel composite coating on the surface of the second-phase particles. The compatibility of nickel and iron is utilized to improve the interfacial bonding between the second-phase particles and the iron matrix, reducing the number of holes and defects between the interfaces, making the material denser as a whole and reducing the possibility of interphase corrosion, thereby improving strength and corrosion resistance. Nickel itself is an austenite-forming element, and some nickel melts into the iron matrix in the two-phase interface region, which can cause the iron in the interface region to tend to form a stable austenite structure and also improve the corrosion resistance of the phase interface. As a face-centered cubic structure, the nickel coating makes it easier for carbon formed by methane ionization to enter the coating during subsequent plasma treatment, thereby improving the strength and corrosion resistance of the coating itself.

[0057] Table 1

[0058] experimental group Tensile strength (MPa) Self-corrosion potential (V) Example 1 656.1 -0.755 Example 2 669.7 -0.721 Example 3 673.2 -0.703 Example 4 670.9 -0.710 Comparative Example 1 575.4 -0.886 Comparative Example 2 611.8 -0.805 Comparative Example 3 632.2 -0.798

[0059] The technical solutions provided by the present invention are described in detail above. For those skilled in the art, according to the ideas of the embodiments of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing a corrosion-resistant steel strip, characterized in that the steps include: (1) preparing a chemical plating solution, wherein the components of the chemical plating solution are nickel sulfate, sodium hypophosphite, ammonium acetate, trisodium citrate, cerium dioxide powder, glycine, thiourea, sodium lauryl sulfate and water; the concentrations of the components in the chemical plating solution are: nickel sulfate 25-27 g / L, sodium hypophosphite 22-24 g / L, ammonium acetate 18-20 g / L, trisodium citrate 25-26 g / L, cerium dioxide powder 1-2 g / L, glycine 1-3 g / L, thiourea 0.4-0.5 mg / L, sodium lauryl sulfate 0.8-1 mg / L, and the solvent is water; adding niobium carbide powder The powder is ball-milled and sieved to obtain a sieved powder, the sieved powder is immersed in acetone, stirred under an ultrasonic environment for more than 20 minutes, and then solid-liquid separation is performed, the solid phase is dried at 60° C. for more than 2 hours, and the dried solid phase is immersed in the chemical plating solution, and the mass ratio of the dried solid phase immersed in the chemical plating solution is solid phase: chemical plating solution = 1:30-50; heating to 80±5° C. in a water bath and plating at a constant temperature for more than 60 minutes, condensing and refluxing during the plating process; after the plating is completed, the solid-liquid separation is performed, the solid phase is washed with deionized water for more than 3 times, and dried at 60° C. for more than 3 hours to obtain a plating powder; (2) placing the plated powder on a cathode disk in a plasma glow nitriding furnace, and subjecting it to glow plasma treatment in an environment of a mixture of hydrogen and methane at a voltage of 700-750 V, a pressure of 400-450 Pa, and a treatment time of 6-10 h. After the treatment, the powder is cooled to room temperature in a hydrogen protective atmosphere to obtain a plasma-treated powder; (3) mixing carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder uniformly to obtain mixed alloy powder, heating the mixed powder to 1600-1620° C. to melt into a melt, stirring with bottom argon blowing for 20-30 minutes, desulfurizing, deoxidizing, and skimming, and then adding the plasma-treated powder, continuing to stir with bottom argon blowing for 4-5 minutes after adding the materials, and then immediately pouring into a mold for casting to obtain a cast plate; (4) The cast slab is heated to 1200-1280° C. and subjected to a constant temperature homogenization treatment for 100-120 min, and then rough-rolled into a strip at 1100-1160° C., and then subjected to 5-7 rounds of finish rolling to form the corrosion-resistant steel strip, with the final rolling temperature being above 950° C.

2. The method for preparing a corrosion-resistant steel strip according to claim 1, characterized in that: In the step (2), the volume ratio of hydrogen to methane in the hydrogen and methane mixed gas is hydrogen:methane=100:0.8-1.

3. The method for preparing a corrosion-resistant steel strip according to claim 1, characterized in that: In the step (3), the carbon steel powder is 20# carbon steel powder; the weight percentage of Cr in the Fe-Cr alloy powder is 60wt%; the weight percentage of Mo in the Fe-Mo alloy powder is 55wt%; the weight percentage of Si in the Fe-Si alloy powder is 75wt%; the weight percentage of Al in the Fe-Al alloy powder is 50wt%; the mixed weight ratio of carbon steel powder, Fe-Cr alloy powder, Fe-Mo alloy powder, Fe-Si alloy powder and Fe-Al alloy powder is carbon steel powder: Fe-Cr alloy powder: Fe-Mo alloy powder: Fe-Si alloy powder: Fe-Al alloy powder = 100: 0.7~0.8: 1~2: 0.9~1.2: 0.6~1.

6.

4. The method for preparing a corrosion-resistant steel strip according to claim 1, wherein: In the step (3), the weight of the plasma-treated powder added is 1.2% to 1.5% of the total weight of the mixed alloy powder.