30results about How to "Achieving grain refinement" patented technology

The invention relates to a preparation method of an ultrafine-grain titanium matrix composite material by using a mushy-zone titanium alloy as a matrix. The preparation method comprises the following steps: carrying out hot working of a titanium matrix composite material; cutting to form a blank material, and polishing; simultaneously preheating a sample and a die, and uniformly smearing the surface of the sample and the inner wall of the die with a graphite lubricant; respectively carrying out heating and heat insulation of the die and the sample; putting the sample in a die channel to make the sample completely go through the channel corner of the equal-diameter corner extrusion die, and cooling the sample with water to complete a primary extruding technology; and machining the sample, carrying out 90DEG anticlockwise rotation, beveling the head, and carrying out 2-4 time equal-diameter bending channel extrusion deformation to obtain the ultrafine-grain titanium matrix composite material. The preparation method realizes the strength and plasticity deformation of the titanium matrix composite material, effectively refines the internal crystal grain size, has the advantages of short process flow, easy operation, high efficiency, low cost and strong adaptability, and can be used in the titanium matrix composite material processing field.

The invention relates to a processing method for refining crystal grains and improving texture of double surface layers of a magnesium alloy plate strip. In the method, the magnesium alloy plate strip is arranged between at least two groups of bending rolls which are stacked up and down and staggered mutually at the temperature of between 250 and 400 DEG C; the magnesium alloy plate strip is driven to move towards one direction for at least one pass, and when passing through the bending rolls, the magnesium alloy plate strip are bent and deformed, so the magnesium alloy plate strip of which the crystal grains of the double surface layers are refined and the texture is improved is prepared. In the deformation process, large strain is accumulated on the upper and lower surface layers of the plate strip due to repeated stretching and compression, and dynamic recrystallization is induced at middle and high temperature, so that the crystal grains of the double surface layers of the plate strip are refined; and the surface layers are subjected to shear stress, so that a basal plane deflects to improve the original texture. In the method, a process design is reasonable, and equipment is simple and convenient to operate, can be matched with the conventional processing equipment for magnesium alloy, has high processing efficiency and can improve the rigidity and ductility of the double surface layers of the magnesium alloy plate strip effectively and improve the subsequent processing performance of the magnesium alloy plate strip; and large-scale industrial production is easy to realize.

The invention discloses a compound treatment purifying method of a magnesium alloy melt. The method comprises the following step: carrying out gas blowing stirring treatment while purifying the magnesium alloy melt by a refining flux, wherein the refining flux can purify and remove bigger inclusions of the magnesium alloy melt, and meanwhile, bubbles of inert gases or nitrogen introduced by gas blowing stirring enable the inclusions suspended in the magnesium alloy melt to quickly come up to the surface of the melt, so that inclusions in the magnesium alloy melt are effectively removed, particularly fine inclusions, thereby improving the quality of a magnesium alloy to a great extent. Furthermore, the method further promotes homogenization of magnesium alloy components, improves the yield of a zirconium refiner and controls segregation of zirconium element. Therefore, the method disclosed by the invention has the compound purifying and refining functions, and is short in treatment time, simple and suitable for experimental and industrial applications.

The invention relates to a rolling-deformation thermal treatment method for improving performance of a bearing ring. The rolling-deformation thermal treatment method comprises the steps of carrying out roll forming on a bearing ring blank to break crystal grins, generating a lot of crystal defects like dislocation and substructures inside the material, and enlarging recrystallization nucleation positions; then, carrying out quenching treatment, dynamic recrystallization nucleation, solid state phase change and dispersion strengthening, and refining the crystal grains to improve the distribution uniformity of the crystal grins; and decreasing the content of retained austenite in the bearing ring through cold treatment, so as to improve the strength, rigidity, toughness and structure stability of the bearing ring considering the problems that the structure quickly cooled through oil quenching or water quenching has retained austenite with a relatively high content, and the retained austenite with the relatively high content influences the size accuracy stability and reduces the strength, rigidity, plasticity and fatigue crack propagation resistance of the bearing ring. According to the rolling-deformation thermal treatment method, the fineness uniformity, mechanical property and size stability of the bearing ring structure are remarkably improved.

The invention relates to a tin plating electrolyte which contains a solvent and the materials with following concentration: 10-20g / L of tin methane sulfonate, 30-60g / L of methanesulfonic acid, 0.4-5g / L of compound additive, and a proper amount of PH regulator; and the compound additive is formed by thiourea, hydroquinone, 2-mercapto benzimidazole and propylene glycol block polyether. For the tin plating electrolyte, by reasonably selecting types and use amount of additives, the problems of instable plating solution and high cost in the methanesulfonic acid system are solved, and by using the tin plating electrolyte, a high-mass plating layer is acquired beneficially.

The invention discloses a rotary deep drawing forming mold of a thin-wall cup-shaped part. The mold comprises a punch, a forming female mold and a lower mold plate, the forming female mold is coaxially provided with a composite mold cavity allowing a blank to be placed in, the end face of the contact of the punch and the blank is a conical boss mold face, the composite mold cavity is formed through compositing of a V mold cavity in the upper portion and a rectangular mold cavity in the lower portion, the two sides of the connecting position of the V mold cavity and the rectangular mold cavityare each provided with multi-pass arc convex face tables making contact with the blank, the multi-pass arc convex face tables are sequentially mounted from top to bottom, the arc radii of the convex face tables are sequentially increased, the number of the arc convex face tables on one side is larger than that of the arc convex face tables on the other side by one, the forming die mold is an asymmetric annular rotation body, the additional arc convex face table is mounted on the highest position on the side, according to the mold, the steel forming property can be improved, the forming component comprehensive mechanical property can be improved, and the defect that strength differences of all directions of a traditional thin drawing forming thin-wall cup-shaped part are large can be overcome.

The invention relates to a magnesium alloy extrusion combined die. The magnesium alloy extrusion combined die is formed in a way that a variable-extrusion ratio casting extrusion die, an equal-channel corner die and an extrusion punch are combined, wherein the variable-extrusion ratio casting extrusion die, the equal-channel corner die and the extrusion punch are detachable; the extrusion punch is installed at a feed opening of the variable-extrusion ratio casting extrusion die, and the equal-channel corner die is installed at a discharge opening of the variable-extrusion ratio casting extrusion die; and the extrusion punch is in a shape of sand glass, a funnel-shaped vertical channel is formed in a die cavity in the variable-extrusion ratio casting extrusion die, a channel of a die cavity in the equal-channel corner die forms corners from 0 to 90 degrees together with the upper and lower planes of the die, and the fillet radius of each corner is 3 mm. Magnesium alloy after chilling casting is assembled with the die and is heated and then is put on a forging press for forward extrusion, so that the grain refinement of the magnesium alloy can be realized, and the cross section of an obtained magnesium alloy bar has the advantages of small grains, uniform tissues and excellent mechanical properties.

A variable cross-section rotary extrusion die and its use method, including a punch and a die, the die is provided with a forming cavity; the forming cavity includes an introduction section, and the lower end of the introduction section is connected to a threaded section of a multi-stage rotary extrusion section The upper end of the threaded section of the multi-stage rotary extrusion section is connected to the outlet section; the punch is set in the introduction section; when in use, the punch squeezes the first preformed blank, and when the punch coincides with the introduction section, the extrusion device is closed ; Open the extrusion device again, when the punch comes out from the forming cavity of the die completely, place the second pre-deformed blank in the introduction section of the forming cavity of the die, open the extrusion device, the punch and the introduction When the lower end surfaces of the segments are overlapped, the extrusion device is closed, and the second pre-deformed billet will squeeze the first pre-deformed billet out of the forming cavity of the die, and the first pre-deformed billet passes through the introduction section, the multi-stage rotary extrusion section, and the threaded section in turn. 1. Deformation of the lead-out section to complete the variable cross-section rotary extrusion deformation of the first preformed blank; the invention has the advantages of simple process and high forming efficiency.

The invention provides a preparation method of powder metallurgy austenitic stainless steel. The preparation method comprises the following steps that austenitic stainless steel powder, yttrium oxidepowder and a lubricating agent are mixed, and mixed powder is obtained; the then the mixed powder is pressed and sintered in sequence, and the powder metallurgy austenitic stainless steel is obtained.The mass of the yttrium oxide powder accounts for 0.2% to 0.4% of the mass of the mixed powder. The austenitic stainless steel powder and the yttrium oxide powder are adopted as raw materials, a certain amount of yttrium oxide powder is added as a stabilizing agent, and precipitated phases can be reduced at high temperature. Meanwhile, the yttrium oxide powder can be dispersed and distributed ina matrix, matrix grain refinement is achieved, and then the porosity is reduced; and the shape and dimension of occluded foreign substances are improved, the number of the occluded foreign substancesin the steel is reduced, and the number of corrosive pitting inducing sources is effectively reduced. Meanwhile, rare earth oxide in the steel can be effectively desulfurated, the number of the occluded foreign substances in the steel can be reduced, the occluded foreign substances can be modified, and therefore the corrosion resistance of the steel matrix is enhanced.

The invention discloses a welded joint fatigue life prolonging method and belongs to the technical field of surface strengthening processing for improving the fatigue property of a metal welding seam.According to the welded joint fatigue life prolonging method, the surface spinning strengthening technology is adopted to carry out surface strengthening processing on a welded joint so as to obtaina metal surface layer microstructure with hardness gradient, so that surface strengthening and hardening of the metal welded joint are realized; and in addition, the processing surface is smooth, so that the surface stress concentration level and the postwelding residual stress level of a welded component are lowered. When the metal welded component takes service under the action of cyclic load, afatigue crack can be restrained from generating on the surface of the welded joint after spinning processing to improve the fatigue property of the metal welded joint.

The invention provides marine ultrahigh-strength low-temperature steel with excellent fatigue performance and a manufacturing method thereof. The steel comprises the following components in percentage by weight: 0.080%-0.140% of C, 0.20%-0.60% of Si, 1.15%-1.60% of Mn, 0.020%-0.050% of Nb, 0.040%-0.080% of V, 0.30%-0.50% of Cu, 0.50%-0.80% of Ni, 0.0140%-0.057% of N, 0.10%-0.20% of Cr, less than or equal to 0.010% of P, less than or equal to 0.005% of S, 0.015%-0.035% of Als and the balance of Fe and inevitable impurities. The preparation method comprises the steps of smelting, continuous casting, heating, rolling and cooling. The microscopic structure of the low-temperature steel produced through the method is a complex-phase structure of superfine ferrite, bainite and a small amount of martensite, the room-temperature high-cycle fatigue ultimate strength is 320 MPa or above, the fatigue ratio is larger than or equal to 0.52, and the-20 DEG C high-cycle fatigue ultimate strength is 350 MPa or above; according to the low-temperature steel, the yield strength is 500 MPa or above, the tensile strength is 620 MPa or above, the percentage elongation after fracture is 23.0% or above, the impact absorption energy at the temperature of-40 DEG C is larger than or equal to 260 J, and the impact absorption energy at the temperature of-60 DEG C is larger than or equal to 230 J.

The invention discloses a method for prolonging fatigue life of welded joints, and belongs to the technical field of surface strengthening processing for improving the fatigue performance of metal welds. This method adopts surface spinning strengthening technology to carry out surface strengthening processing on welded joints to obtain metal surface structure with hardness gradient, realize surface strengthening and hardening of metal welded joints, and process smooth surface at the same time, which reduces the level of stress concentration and stress concentration on the surface of welded components. Post-weld residual stress levels. When metal welded components serve under cyclic loads, the initiation of fatigue cracks from the surface of welded joints can be inhibited after spinning, thereby improving the fatigue performance of metal welded joints.

The invention discloses a full-automatic integrated preparation device for metal material grain refinement and forming. The full-automatic integrated preparation device comprises an automatic rotatingsystem, an automatic die changing system, an extrusion forming system and an automatic die locking device, wherein the extrusion forming system is arranged at one end of the automatic rotating system, the automatic die locking device is arranged on one side of the extrusion forming system, and the automatic die changing system is arranged at the bottom end of the extrusion forming system. The full-automatic integrated preparation device has the beneficial effects that metal which only being suitable for casting machining in the past realizes grain refinement, extrusion forming can be completed at a time after toughness improvement, after the process is fully automatic, a series of machining can be completed in a short time, the temperature of a material is basically not reduced, and reheating and heat preservation are not needed, so that the time is saved, the efficiency is improved, the energy is saved, the cost is reduced, the range of the material capable of being subjected to plastic forming is widened, and a high-strength workpiece which cannot be machined by the plastic forming previously can be prepared.

The invention provides a suspension type flash butt welding and medium-frequency heat treatment mechanism for steel rails. The suspension type flash butt welding and medium-frequency heat treatment mechanism comprises a medium-frequency heat treatment mechanism (1), a welding machine static frame (2), a welding machine moving frame (3) and a suspension frame (4). The suspension type flash butt welding and medium-frequency heat treatment mechanism is characterized in that the medium-frequency heat treatment mechanism (1) is fixed between the welding machine static frame (2) and the welding machine moving frame (3); and the top end of the welding machine static frame (2) and the top end of the welding machine moving frame (3) are connected and fixed through the suspension frame (4). Throughthe suspension type flash butt welding and medium-frequency heat treatment mechanism for the steel rails, flash welding of the steel rails and joint heat treatment in the locked state are completed ata time, two procedures are combined into one, and the working hours are shortened at least one time for site operation. Through invention of a heat treatment slag stopping mechanism, effective isolation of welding spattering during welding of the steel rails from the heat treatment mechanism is realized.

The invention belongs to the field of material welding and particularly relates to a vibration, impact and extrusion method for eliminating weld joint residual stress. According to the vibration, impact and extrusion method, a vibration impact source device which generates vibration impact force is arranged over an extrusion wheel which parallelly moves along weld joints; and when the extrusion wheel parallelly moves along the surfaces of the weld joints, the vibration impact force generated by the vibration impact source device and extrusion force of the extrusion wheel jointly act on the weld joints coaxially in the same direction, so that the weld joints are locally compressed and deformed, and the weld joint residual stress is eliminated. Compared with weld joint residual stress eliminating through an original extrusion method, the application range is wider, the post-welding residual stress of the thin plate weld joints, the middle-thick plate weld joints and the high-strength weld joints can be eliminated, eliminating of the weld joint residual stress or generation of negative stress particularly facilitates long-term storage and safe use of welded structural parts without the harmful stress effect, and significant using value is achieved on welding of ships, vehicles, artilleries and ammunition and stable use of various storage and transport containers for nuclear powerfor decades.

The invention provides a high-toughness plastic die steel and a production method thereof. The die steel comprises the following chemical components in percentage by mass: 0.30-0.42% of C, 0.20-0.50% of Si, 0.75-1.00% of Mn, 1.50-2.00% of Cr, 0.25-0.50% of Mo, at most 0.015% of S, at most0.025% of P, 0.010-0.040% of Als and the balance of Fe and inevitable impurities. According to the production method of the high-toughness plastic die steel, a normalizing-tempering technique is utilized to product the die steel to implement grain refinement, so that the product hardness is up to 28-32 HRC, the uniformity of hardness is favorable, the Charpy V-notch ballistic work is up to higher than 80J, and the product specification can cover 20-120mm.

The invention discloses a rotary deep drawing forming method of a thin-walled cup-shaped part, which includes ① blanking, ② homogenizing heat treatment, ③ heating and heat preservation of the blank and the mold, ④ putting the blank into a V-shaped cavity, and the punch rotates on the top Driven by the hydraulic press, it moves downwards, and first touches the upper surface of the blank, and the punch moves downward at a constant speed, so that the metal on the contact surface flows into the groove on the end face of the punch one after another, and is integrated with the punch, and the punch drives the blank to start torsion and Press down, and at the same time, the peripheral part of the billet is squeezed and flows into the multi-pass arc convex platform. First, one side of the peripheral metal touches the first round arc convex platform, forming a height difference with the other side, and then makes the In the next downward twisting deformation process, the speed difference is formed on both sides, and finally squeezed into the rectangular cavity until it moves to the specified position. This case can improve the formability of steel materials, improve the comprehensive mechanical properties of formed components, and overcome the shortcomings of the large difference in anisotropic strength of thin-walled cup-shaped components formed by traditional thinning and deep drawing.

The invention discloses a laser impact grain refinement pretreatment auxiliary laser dynamic flexible micro-forming method and device, and relates to the field of laser processing and forming. The device comprises a laser loading system, a plastic forming system, an automatic mold changing system and a clamp system. According to the method, a workpiece is subjected to laser impact pretreatment toachieve grain refinement and then subjected to laser dynamic flexible micro-forming, and grain refinement pretreatment and forming machining are achieved through a movable mold core and a mold core supporting body. According to the method and device, the novel micro-mold is used for carrying out laser impact grain refining pretreatment before laser dynamic flexible micro-forming, so that the forming capability is improved, the micro-forming precision, the surface quality and the forming limit are further improved, and failure behaviors such as breakage caused by a size effect phenomenon are avoided; and meanwhile, the novel automatic mold changing system for the micro mold can avoid secondary clamping, so that the production cost is effectively saved.

The invention relates to a preparation method of an ultrafine-grain titanium matrix composite material by using a mushy-zone titanium alloy as a matrix. The preparation method comprises the following steps: carrying out hot working of a titanium matrix composite material; cutting to form a blank material, and polishing; simultaneously preheating a sample and a die, and uniformly smearing the surface of the sample and the inner wall of the die with a graphite lubricant; respectively carrying out heating and heat insulation of the die and the sample; putting the sample in a die channel to make the sample completely go through the channel corner of the equal-diameter corner extrusion die, and cooling the sample with water to complete a primary extruding technology; and machining the sample, carrying out 90DEG anticlockwise rotation, beveling the head, and carrying out 2-4 time equal-diameter bending channel extrusion deformation to obtain the ultrafine-grain titanium matrix composite material. The preparation method realizes the strength and plasticity deformation of the titanium matrix composite material, effectively refines the internal crystal grain size, has the advantages of short process flow, easy operation, high efficiency, low cost and strong adaptability, and can be used in the titanium matrix composite material processing field.

The invention discloses an anodic oxidation aluminum alloy. The anodic oxidation aluminum alloy mainly comprises, by weight, 0.6-1.2% of Si, 0-0.2% of Fe, 0.1-0.6% of Cu, 0-0.15% of Mn, 1.0-1.4% of Mg, 0-0.03% of Cr, 0-0.1% of Zn, 0-0.1% of Ti, and the balance Al. According to the anodic oxidation aluminum alloy, an improvement is made on the chemical components of the aluminum alloy; a manufactured and prepared aluminum alloy plate strip has the yield strength of more than 330 MPa, the tensile strength of more than 370 MPa and the Vickers hardness of more 130 HV; grain refinement is achieved,and the grain size is less than 80 microns; the high strength and high uniformity are achieved; the roughness of a plate is controlled within Ra 0.1-0.3 microns. The alloy has excellent anodic oxidation effect and high strength and hardness, has high lustrous surface and can be extensively applied to high-end anodic oxidation products, especially the field of 3C electronic product shells such asmobile phones, tablet computers, notebook computers, all-in-on PCs, routers and game machines. Moreover, the preparation method is simple, easy to grasp and convenient to implement.

The invention discloses steel for a damping piston rod for an automobile and a production method of the steel. The steel for the piston rod comprises, by mass percent, 0.34%-0.36% of C, 0.19%-0.24% of Si, 0.67%-0.73% of Mn, not larger than 0.030% of P, 0.025%-0.030% of S, 0.020%-0.040% of Al and the balance Fe and inevitable impurities. The production method comprises the procedures of converter smelting, LF furnace refining, RH furnace refining, continuous casting, cogging, heating furnace treatment, rolling and cooling. According to the produced steel for the damping piston rod, the tensile strength is larger than or equal to 530 MPa, the percentage elongation after fracture is larger than or equal to 20%, the grain size is larger than or equal to the sixth stage, total oxygen in the steel is smaller than or equal to 0.002%, a decarburized layer is smaller than or equal to 1.0%D, and the requirement of the steel for the damper piston rod for the automobile can be effectively met.

The invention relates to a metallurgical technology, and specifically relates to 700MPa-grade high-strength hot-rolled H-shaped steel and a preparation method thereof. The 700MPa-grade high-strength hot-rolled H-shaped steel comprises the following chemical components in percentage by weight: 0.05-0.10% of C, 0.20-0.50% of Si, 1.30-1.60% of Mn, not greater than 0.020% of P, not greater than 0.008% of S, 0.32-0.50% of Cu, 0.70-0.90% of Cr, 0.32-0.50% of Ni, 0.20-0.30% of Nb, 0.45-0.60% of V and the balance iron and trace impurities. According to the 700MPa-grade high-strength hot-rolled H-shaped steel and the preparation method thereof, heating and rolling are mainly controlled in a combination manner through a component design; and meanwhile, production for the 700MPa-grade high-strength hot-rolled H-shaped steel is realized by virtue of rapid cooling. The product disclosed by the invention is high in mechanical property, and has a yield strength of greater than 700MPa and a tensile strength of greater than 800MPa. Compared with a preparation method for traditional high-strength steel, the preparation method disclosed by the invention has few production procedures and is low in production cost due to no need of online heat treatment and heat treatment after rolling during a production process.

The invention belongs to the field of biomedical materials and particularly relates to an absorbable orthopedic implanted magnesium alloy. The absorbable orthopedic implanted magnesium alloy comprises, by mass, 4.0-8.0% of Zn, 0.8-2.0% of Y, 0.6-2.0% of Nd, 0.2-0.4% of Sc, and the balance Mg. The invention further discloses a preparation method of the absorbable orthopedic implanted magnesium alloy. According to the method, the absorbable orthopedic implanted magnesium alloy is formed by melting magnesium ingots, zinc ingots, a Mg-Y intermediate alloy, a Mg-Nd intermediate alloy and a Mg-Sc intermediate alloy as furnace burden. High-content Zn is added to pure magnesium to serve as a main strengthening element; the high requirement for the strength of the orthopedic implanted material is achieved through solution strengthening and dispersion strengthening; a few rare earth elements Y, Nd and Sc are added compositely to improve the mechanical performance and the corrosion resistance ofthe alloy and achieve the purposes of structure and grain refinement. Through combination of multiple passes of extrusion processing at the big extrusion ratio and annealing heat treatment after extrusion, the superfine-grained magnesium alloy with second phases finely dispersed and distributed in a base body, and the mechanical performance and corrosion resistance of the absorbable orthopedic implanted magnesium alloy are greatly improved.

The invention discloses a laser shock pretreatment-assisted laser dynamic flexible micro-forming method and device, and relates to the field of laser processing and forming. The device includes a laser loading system, a plastic forming system, an automatic mold changing system and a fixture system; Supplemented by laser shock pretreatment to achieve grain refinement and then laser dynamic flexible micro-forming, through the movable mold core and core support body, grain refinement pretreatment and forming processing are realized. The invention uses a new type of micro-mold to make Before laser dynamic flexible micro-forming, laser shock grain refinement pretreatment is performed to improve its forming ability, thereby improving its micro-forming accuracy, surface quality and forming limit, and avoiding failure behaviors such as fracture caused by size effects. . At the same time, the automatic mold change system of the new micro-mould can avoid secondary clamping and effectively save production costs.

The invention provides a steel material for a forged steel brake disc of a high-speed train with the speed of 350 km or above per hour and a forging technology of the steel material. The brake disc is prepared from, by mass, 0.25%-0.29% of C, 0.2%-0.35% of Si, 0.6%-0.9% of Mn, 2.1%-2.5% of Cr, 0.9%-1.1% of Mo, 0.2%-0.3% of V, 0.02%-0.04% of Al, 0.05%-0.08% of Nb and the balance iron and other elements, and the other elements are residual microelements. The blank of steel materials for forging and heat treatment of the high-speed rail brake disc with the speed of 350 km and above in China is filled firstly, the steel materials have the characteristics of fine grain size, uniform structure, normal-temperature performance, low-temperature performance and high-temperature performance, it is guaranteed that various performance requirements of the high-speed rail brake disc with the speed of 350 km and above are met, the raw material cost is saved, and the production cost is reduced. And the range of the steel material for forging the high-speed rail brake disc with the speed of 350 km and above in China can be widened to a certain extent, and localization of the steel material for forging the high-speed rail brake disc with the speed of 350 km and above is achieved.

The invention provides a preparation method of powder metallurgy austenitic stainless steel, comprising the following steps: mixing austenitic stainless steel powder, yttrium oxide powder and lubricant to obtain a mixed powder, and then sequentially pressing and sintering to obtain powder metallurgy Austenitic stainless steel; the mass of the yttrium oxide powder is 0.2-0.4% of the mass of the mixed powder. The invention uses austenitic stainless steel powder and yttrium oxide powder as raw materials, and by adding a certain amount of yttrium oxide powder as a stabilizer, the precipitated phase can be reduced under high temperature conditions, and at the same time, it can be dispersed and distributed in the matrix to achieve matrix grain refinement , thereby reducing porosity, improving the shape and size of inclusions, reducing the number of inclusions in steel, and effectively reducing the number of pitting sources; at the same time, rare earth oxides in steel can effectively desulfurize and reduce inclusions in steel and modify the inclusions, thereby enhancing the corrosion resistance of the steel matrix.