ROLLED BORON STEEL AND ITS PRODUCTION METHOD

Abstract

The invention relates to the field of metallurgy, particularly to the production of high-strength rolled steel used in the manufacture of various types of products, especially parts for agricultural machinery operating under increased abrasive wear conditions, and also in mechanical engineering, equipment, parts and assemblies operating under increased wear conditions. Rolled boron steel contains the following (by weight %): carbon 0.17-0.42; silicone 0.15-0.45; manganese 0.8-1.9; Phosphorus up to 0.03; Chrome up to 0.4? Aluminum up to 0.07? titanium 0.010-0.055; Sulfur up to 0.04? Boron up to 0.005?e; nitrogen maximum 0.012; Iron and inevitable impurities? The rest, Here the content of chemical elements meets the ratio (1): , (1) and meets the boron content ratio (2): ?=0.00056+0.0793Al+0.108N-0.0018Ti (2) Rolled steel contains 0.001-0.005% calcium by weight, and the calcium content conforms to the following ratio: (3) The method for producing rolled boron steel involves melting, casting, hot rolling, accelerated cooling, and winding processes. The invention enables the production of hot-rolled boron steel with a fine-grained structure, excellent mechanical properties, and high crack resistance.

Claims

1. A rolled boron steel containing the following (by weight %): Carbon – greater than 0.17 and less than 0.42; silicone – 0.15-0.45; manganese – 0.8-1.9; phosphorus – up to 0.03; Chromium – up to 0.4; aluminum – up to 0.07; titanium – 0.010-0.055; sulfur – up to 0.04; boron – down to 0.005; nitrogen – down to 0.012; calcium – 0.001-0.005%; iron and inevitable impurities – the rest; Here the content of chemical elements meets the ratio (1): (1) and meets the boron content ratio (2): В=0.00056+0.0793Al+0.108N-0.0018Ti (2) 2. The rolled boron steel submitted pursuant to Claim 1 has the following characteristic of having the following calcium content: the ratio is met: (3).

3. The rolled boron steel submitted pursuant to Claim 1 is rolled boron steel with a heat transfer rate of 450 MPa or higher. with greater yield strength, tensile strength greater than 650 MPa, at least With a relative elongation of 22%, microhardness up to 250 HV, and a score of 10 points or more according to GOST 5639. Ferrite-pearlite with a small grain size and a rating not exceeding 3 points according to GOST 5640. It has a striped pattern.

4. A proposal for the production of rolled boron steel submitted under any of claims 1 to 3. The method involves melting, casting, hot rolling, accelerated cooling, and winding. It involves 35 stages; where the plates are heated to a temperature of up to 1250 °C, hot 9 Rolling is carried out at a temperature of 850-930°C and winding at 610-750°C. It is done at a certain temperature; Here, rolled steel (by weight %) contains the following: carbon – more than 0.17% and less than 0.42%; silicone – 0.15-0.45; manganese – 0.8-1.9; phosphorus – up to 0.03; Chromium – up to 0.4; aluminum – up to 0.07; titanium – 0.010-0.055; sulfur – up to 0.04; boron – down to 0.005; nitrogen – down to 0.012; calcium – 0.001-0.005%; iron and inevitable impurities – the rest; Here the content of chemical elements meets the ratio (1): (1) and meets the boron content ratio (2): В=0.00056+0.0793Al+0.108N-0.0018Ti (2). 1 Specifications ROLLED BORON STEEL AND ITS PRODUCTION METHOD Field of Invention The invention has implications for the field of metallurgy, particularly in the manufacture of various types of products, especially those with increased demand. in the manufacture of parts for agricultural machinery operating under abrasive wear conditions, and also in mechanical engineering, equipment, parts and assemblies operating under increased wear conditions It relates to the production of high-strength rolled steel used. Previous Technique The previous technique (RU 2337151) involved certain non-metallic components with respect to structural and mechanical properties. hot-rolled continuous casting pipe billet made of boron alloy steel It explains that the billet is made of steel containing the following component ratios (by weight %): It is characterized by: carbon 0.26-0.30; manganese 1.20-1.40; silicone 0.17-0.37; chromium 0.40-0.65; nickel 0.005-0.25; copper 0.005-0.35; aluminum 0.02-0.06; titanium 0.02-0.05; boron 0.001-0.004; nitrogen 0.005-0.010; arsenic 0.0001-0.03; tin 0.0001-0.02; lead 0.0001-0.01; zinc 0.0001-0.005; iron and inevitable impurities – the rest, 35. When the following relationships are met: (arsenic + tin + lead + 5 zinc) ≤ 0.07; 2 -3 (titanium / 48 + aluminum / 27 + nitrogen / 14) ≤ (0.6 10 ), It is normalized; it has a ferrite-pearlite structure; the true grain size is 6-9 points; central It has a macrostructure containing porosity; point heterogeneity and quadratic decomposition. Available; seeding separation is no more than 3 points for each type; separation lanes 2 not more than a certain number of points; sulfides, point oxides, stranded oxides, brittle silicates, plastics Silicates, undeformed silicates, tensile strength not exceeding 4.0 points for each type. Yield strength is not less than 862 N / mm², relative elongation is not less than 758 N / mm². It is not less than 11.5%, and the relative shrinkage is not less than 34%. Steel contains the following unavoidable impurities (by weight %): sulfur (maximum 0.025%) and phosphorus (maximum 0.025%). During steel production, the hot rolling process of rolled steel takes place at a temperature of 1180-1150 °C. It begins and ends at a temperature of 840-950 °C. One disadvantage of this steel is its high silicon content and low manganese content; this makes the steel... This prevents it from achieving a combination of high strength, sufficient toughness, and flexibility. This situation, This leads to the formation of unwanted residues and cracks in the steel. EP 2184373, 6-12 mm, has excellent strength and impact toughness after heat treatment. It describes high-strength hot-rolled thick steel sheet of a certain thickness; where steel Its composition is 0.10 to 0.20% C, 0.01 to 1.0% Si, 0.5 to 2.0% Mn, and 0.03% or less P by weight. 0.01% or less S, 0.01% to 0.10% Al, 0.005% or less N, 0.01% to 0.15% Ti, and It contains 0.0010% to 0.0050% B; the remainder consists of Fe and incidental impurities; also the area ratio. It contains a bainitic ferrite phase of 95% or more; where the hardness deviates along the thickness. It is within 10% of the average value; tensile strength 440 to 640 MPa and elongation 20% or There are more. The disadvantages of this steel sheet are its low tensile strength and the significant amount of bainite in the steel. Its presence reduces flexibility and leads to cracking. The closest prior technique to the requested technical solution is high-strength rolled steel. The document describing this is RU 2761572. Rolled steel, in the following proportions of the specified components. (by weight %) carbon, silicon, manganese, phosphorus, sulfur, chromium, nickel, copper, molybdenum and It contains 35% aluminum: 3 carbon 0.2-0.65; silicone 0.1-1.7; manganese 0.15-0.9; phosphorus up to 0.02; sulfur up to 0.015; chromium 0.1-2.0; nickel 0.7-2.2; copper up to 0.5; molybdenum 0.1-0.9; aluminum 0.005-0.15; Thickness of 1.5 to 50 mm, hardness of 160-400 HB, average grain size not exceeding 8 points, and a structure with a non-metallic residue size not exceeding 4 points and less than 3% on both sides It has a relatively shallow general decarburization zone depth. Rolled steel also Up to 0.005% calcium by weight, 0.001-0.3% titanium by weight, up to 0.03% nitrogen by weight and contains up to 0.02% boron by weight. Rolled steel has an initial temperature of 980-1100 °C. It is produced at a rolling temperature, with a final rolling temperature of 880-950 °C, and the winding process It is carried out in a temperature range of 650-750 °C. One disadvantage of the steel in the closest previous technology is its low strength and insufficient flexibility; this This also leads to crack formation. Brief Description of the Invention The technical purpose of the claimed invention is to produce a product with a fine-grained structure, excellent mechanical properties, and The goal is to produce hot-rolled boron steel with high crack susceptibility. The technical result of the claimed invention is a fine-grained structure, excellent mechanical properties, and It consists of producing a hot-rolled boron steel with high crack susceptibility. The problem described concerns a boron-containing hot-rolled steel (%) that includes the following: The problem is solved by its production, and the desired technical result is achieved: carbon 0.17-0.42; 35 silicone 0.15-0.45; manganese 0.8-1.9; 4 phosphorus up to 0.03; Chrome up to 0.4; aluminum up to 0.07; titanium 0.010-0.055; sulfur up to 0.04; Boron down to 0.005; nitrogen up to 0.012; iron and inevitable impurities – the rest. The composition of chemical elements conforms to ratio (1): . (1) Containing carbon, manganese, chromium, phosphorus, sulfur and titanium in amounts that meet Ratio (1). Rolled steel has a fine-grained structure and excellent mechanical properties. The boron content in rolled steel meets the ratio (2): В=0.00056+0.0793Al+0.108N-0.0018Ti (2). Rolled steel containing boron in the amount that meets ratio (2) has an effective boron content of 90-95%. It is used to produce steel with this content. Within this effective boron content, the boron solid solution It is in this state and does not precipitate as dispersed particles of boron nitride. Without adhering to any particular theory, the inventors believe that the above technical result is entirely... that it results from the synergistic effect of the above components and their ratios He believes. The combination of the above features is sufficient to achieve the desired technical result. The following features ensure that the desired technical result is achieved in the most effective way. The requested rolled steel also contains 0.001-0.005% calcium by weight; Here the calcium content meets ratio (3): (3) 35 5 In the equations and inequalities above, the letter symbols represent the corresponding chemical compound as a percentage by weight. It indicates the element's content (for example, "B" represents the boron content in % by weight, "Mn" represents % by weight). (expresses manganese content, etc.). Rolled steel with calcium content conforming to ratio (3), non-metallic in steel The residues are polygonal morphological calcium sulfides instead of elongated manganese sulfides. It allows for modification by creating a fine-grained structure, resulting in excellent mechanical properties. It enables the production of steel with specific properties and increased crack susceptibility. The required yield strength of the rolled steel is greater than 450 MPa, and the tensile strength is 650 MPa. Hardness greater than MPa, relative elongation at least 22%, microhardness not exceeding 250 HV, according to GOST 5639. grain size not greater than 10 and ferritic-pearlitic with a rating not exceeding 3 points according to GOST 5640. The structure has a striped layout. Yield strength, tensile strength (ultimate tensile strength), relative elongation, microhardness, Rolled steel with grain size and banding within the ranges above has a fine-grained structure. It has excellent mechanical properties and high crack susceptibility; this makes it suitable for boron steels. It allows for the expansion of the application area. According to the claimed invention, rolled boron steel is subjected to increased abrasive wear conditions. as well as parts of working agricultural machinery, operating under increased wear conditions. It can also be used in mechanical engineering, equipment, parts and assemblies. The required boron-based hot water... The production method of rolled steel involves melting, casting, hot rolling, accelerated cooling, and It includes winding processes. The sheets are heated to a temperature not exceeding 1250 °C, hot rolling 850- The process is completed at a temperature of 930°C, and the winding process is carried out at a temperature of 610-750°C. Rolling the steel under the temperature conditions mentioned above results in a fine-grained structure and excellent performance. It produces steel with mechanical properties and high crack resistance, and boron steels. It expands the field of application. Calcium is added to steel in the form of wire. The calcium wire is injected into the liquid steel during secondary metallurgy. It is done. Adding calcium to steel results in a fine-grained structure, excellent mechanical properties, and high yields. It produces steel with a crack susceptibility of 35 and expands the application area of ​​boron steels. 6 Rolled boron steel produced by the method of the claimed invention has increased abrasive wear. In addition to the parts of agricultural machinery operating under these conditions, increased wear and tear conditions It can also be used in mechanical engineering, equipment, parts, and assemblies that operate underneath. Regulations of the Invention Tables 1-3 provide examples of steel compositions and their mechanical properties. The explanations are for illustrative purposes only. For a person knowledgeable in the field, the essence of the invention can be understood. It is clear that other arrangements are possible without making any changes. Detailed Explanation of the Regulations Table 1. Compositions of rolled boron steel presented according to the claimed invention, previous It presents it in a comparative manner using technology. The production method for the requested hot-rolled boron steel is melting, casting, and hot rolling. It involves accelerated cooling and winding processes. Billet heating reaches up to 1250 °C. performed at a temperature, hot rolling completed at a temperature of 850-930 °C and winding The process was carried out at a temperature of 610-750 °C. The conditions for the production of rolled boron steel are given in Table 3. Table 1. Chemical compositions of rolled boron steel. Compositions C Si Mn P Cr Al Ti SBN Ca Iron and inevitable impurities Previous 0.2 0.6 0.72 0.012 0.47 0.04 0.003 0.01 0.0002 0.01 0.002 Remainder technical 1 0.17 0.15 0.8 0.01 0.4 0.05 0.01 0.001 0.005 0.004 0.003 Remainder 2 0.42 0.45 1.9 0.02 0.38 0.04 0.01 0.02 0.005 0.011 0.004 Remaining 3 0.23 0.39 1.2 0.008 0.35 0.03 0.055 0.007 0.004 0.012 0.005 Remaining 4 0.38 0.32 0.9 0.02 0.25 0.025 0.032 0.0018 0.003 0.005 0.004 Remaining 0.25 0.26 1.8 0.03 0.15 0.02 0.01 0.002 0.003 0.012 0.001 Remaining 6 0.42 0.39 1.7 0.01 0.4 0.049 0.035 0.02 0.005 0.006 0.003 Remaining Table 2 presents the properties of rolled boron steel, as presented according to the claimed invention and previous technical data. It presents the invention in a comparative manner. 7 Table 2. Properties of rolled boron steel. Parameters: Tensile strength, Yield strength, Relative elongation, Hardness, Grain size, Banding. strength, resistance, %; HV; MPa MPa Previous 1280 - 12 355 8 - technical 1 650 450 22 250 10 3 2 720 540 22 199 11 3 3 650 450 26 175 11 2 4 670 470 25 180 11 3 680 490 23 180 11 2 6 725 550 23 190 12 3 Table 3 shows the production of rolled boron steel, as presented according to the claimed invention. The conditions are presented in comparison with the previous technical invention. Table 3. Conditions for the production of rolled boron steel. Parameters: Billet heating, during winding at the end of rolling. temperature during, °C temperature, °C temperature, °C Previous technical 1100 945 740 1 1200 850 610 2 1250 890 620 3 1200 900 620 4 1200 910 700 1230 890 630 6 1250 930 750 The presented results show that, according to the requested technical solution, the rolled steel has a fine-grained structure. It demonstrates excellent mechanical properties and high crack resistance. Thus, the claimed invention possesses a fine-grained structure, excellent mechanical properties, and high By providing rolled steel with crack resistance, it solves the technical problem and improves the technical result. This allows for the expansion of the application area of ​​boron steels.