Material Introduction

　　Steel: Steel is a material made from steel ingots, billets, or steel through pressure processing to achieve various shapes, sizes, and properties. Steel is an indispensable material for national construction and the realization of the four modernizations. It has wide applications and numerous varieties. According to the cross-sectional shape, steel is generally divided into four major categories: profiles, plates, pipes, and metal products. It is further classified into heavy rails, light rails, large profiles, medium profiles, small profiles, cold-bent steel profiles, high-quality profiles, wire rods, medium and thick steel plates, thin steel plates, electrical silicon steel sheets, strip steel, seamless steel pipes, welded steel pipes, and metal products, etc.

　　Characteristics

　　Ferrous Metals: Ferrous metals mainly refer to iron, manganese, chromium, and their alloys.

　　Steelmaking: Steel is obtained by melting pig iron used for steelmaking in a steelmaking furnace according to a certain process.

　　Non-ferrous Metals: Metals other than ferrous metals are called non-ferrous metals, such as copper, tin, lead, zinc, aluminum, as well as brass, bronze, aluminum alloys, and bearing alloys, etc.

　　Related Terminology

　　Carbon Steel: Carbon steel, also known as carbon steel, is an iron-carbon alloy with a carbon content (wc) of less than 2%. In addition to carbon, carbon steel generally contains small amounts of silicon, manganese, sulfur, and phosphorus. According to its use, carbon steel can be divided into three categories: carbon structural steel, carbon tool steel, and free-machining structural steel. Carbon structural steel can be further divided into structural steel for construction and structural steel for machinery manufacturing. According to the carbon content, carbon steel can be divided into low-carbon steel (wc≤0.25%), medium-carbon steel (wc 0.25%~0.6%), and high-carbon steel (wc >0.6%). According to the phosphorus and sulfur content, carbon steel can be divided into ordinary carbon steel (higher phosphorus and sulfur content), high-quality carbon steel (lower phosphorus and sulfur content), and high-grade high-quality steel (even lower phosphorus and sulfur content). Generally, the higher the carbon content in carbon steel, the higher the hardness and strength, but the lower the plasticity.

　　Carbon Structural Steel: This type of steel mainly ensures mechanical properties; therefore, its grade reflects its mechanical properties, represented by Q+number, where "Q" is the first letter of the pinyin for "yield point," and the number represents the yield point value. For example, Q275 indicates a yield point of 275 MPa. If the grade is followed by the letters A, B, C, D, it indicates different steel quality grades, with the content of S and P decreasing sequentially, and the steel quality improving sequentially. If the letter "F" is marked after the grade, it is boiling steel; if "b" is marked, it is semi-killed steel; if neither "F" nor "b" is marked, it is killed steel. For example, Q235-A·F indicates grade A boiling steel with a yield point of 235 MPa, and Q235-c indicates grade C killed steel with a yield point of 235 MPa. Carbon structural steel is generally used directly in the supply state without heat treatment. Usually, Q195, Q215, and Q235 steel have low carbon mass fraction, good weldability, good plasticity and toughness, and certain strength. They are often rolled into thin plates, steel bars, welded steel pipes, etc., used in bridges, buildings, and other structures, and for manufacturing ordinary rivets, screws, nuts, and other parts. Q255 and Q275 steel have slightly higher carbon mass fractions, higher strength, good plasticity and toughness, and can be welded. They are usually rolled into profiles, bars, and steel plates for structural parts and for manufacturing simple machine connecting rods, gears, couplings, pins, and other parts.

　　High-Quality Structural Steel: This type of steel must ensure both chemical composition and mechanical properties. Its grade uses two digits to represent the mass fraction of average carbon in the steel in ten thousandths (wc×10000). For example, 45 steel indicates that the average carbon mass fraction in the steel is 0.45%; 08 steel indicates that the average carbon mass fraction in the steel is 0.08%. High-quality carbon structural steel is mainly used for manufacturing machine parts. Generally, it needs to undergo heat treatment to improve mechanical properties. Different uses exist depending on the carbon mass fraction. 08, 08F, 10, and 10F steel have high plasticity and toughness, excellent cold forming and welding performance, and are often cold-rolled into thin plates, used for making instrument casings and cold-pressed parts on automobiles and tractors, such as car bodies and tractor cabs; 15, 20, and 25 steel are used for making smaller parts with lighter loads, surfaces requiring wear resistance, and cores with lower strength requirements, such as piston pins and templates; 30, 35, 40, 45, and 50 steel, after heat treatment (quenching + high-temperature tempering), have good comprehensive mechanical properties, namely, high strength and high plasticity and toughness, and are used for making shaft parts. For example, 40 and 45 steel are often used for manufacturing crankshafts and connecting rods for automobiles and tractors, main spindles for general machine tools, machine tool gears, and other shaft parts with less stress; 55, 60, and 65 steel, after heat treatment (quenching + medium-temperature tempering), have a high elastic limit and are often used for manufacturing springs with small loads and sizes (cross-sectional dimensions less than 12-15 mm), such as pressure and speed regulating springs, plunger springs, and cold-wound springs.

　　Carbon Tool Steel: Carbon tool steel is a high-carbon steel that is basically free of alloying elements, with a carbon content ranging from 0.65% to 1.35%. It has low production costs, readily available raw materials, good machinability, and can achieve high hardness and wear resistance after processing, so it is a widely used steel grade, used to manufacture various cutting tools, molds, and measuring tools. However, this type of steel has poor red hardness, which means that when the working temperature is greater than 250℃, the hardness and wear resistance of the steel will decrease sharply, losing its working ability. In addition, if carbon tool steel is made into larger parts, it is difficult to harden and is prone to deformation and cracking.

　　Free-Machining Structural Steel: Free-machining structural steel adds some elements that make the steel brittle to the steel, making the chips easy to break into fragments during cutting, thus improving cutting speed and extending tool life. The elements that make the steel brittle are mainly sulfur; lead, tellurium, and bismuth are used in ordinary low-alloy free-machining structural steel. The sulfur content ws of this steel is in the range of 0.08%-0.30%, and the manganese content wMn is in the range of 0.60%-1.55%. The sulfur and manganese in the steel exist in the form of manganese sulfide, which is very brittle and has lubricating properties, making the chips easy to break and improving the quality of the machined surface.

　　Alloy steel, in addition to iron, carbon, and small amounts of unavoidable silicon, manganese, phosphorus, and sulfur, also contains a certain amount of alloying elements. The alloying elements in steel include silicon, manganese, molybdenum, nickel, chromium, vanadium, titanium, niobium, boron, lead, and rare earth elements, either singly or in combination. Steel containing these elements is called alloy steel. Alloy steel systems vary from country to country depending on resource availability, production, and usage conditions. Foreign countries previously developed nickel-chromium steel systems, while China has developed alloy steel systems primarily based on silicon, manganese, vanadium, titanium, niobium, boron, and rare earth elements. Alloy steel accounts for approximately ten to twenty percent of total steel production and is generally smelted in electric furnaces. According to its use, alloy steel can be divided into eight categories: alloy structural steel, spring steel, bearing steel, alloy tool steel, high-speed tool steel, stainless steel, heat-resistant steel, and electrical silicon steel.

　　Ordinary low-alloy steel is a type of ordinary alloy steel containing a small amount of alloying elements (in most cases, the total amount w does not exceed 3%). This steel has relatively high strength, good comprehensive performance, and corrosion resistance, wear resistance, low-temperature resistance, as well as good machinability and weldability. With significant savings in scarce alloying elements (such as nickel and chromium), 1 ton of ordinary low-alloy steel can typically replace 1.2-1.3 tons of carbon steel, and its service life and range of applications far exceed that of carbon steel. Ordinary low-alloy steel can be smelted using general smelting methods in open-hearth and converter furnaces, and its cost is close to that of carbon steel.

　　This refers to alloy steel used in engineering and building structures, including weldable high-strength alloy structural steel, alloy reinforcing steel, railway alloy steel, alloy steel for geological and petroleum exploration, alloy steel for pressure vessels, and high-manganese wear-resistant steel. This type of steel is used for engineering and building structural components. Among alloy steels, this type has a relatively low total alloy content but is produced and used in large quantities.

　　This type of steel refers to alloy steel suitable for manufacturing machines and mechanical parts. It is made by adding one or more alloying elements to high-quality carbon steel to improve the steel's strength, toughness, and hardenability. This type of steel is usually used after heat treatment (such as tempering or surface hardening). It mainly includes commonly used alloy structural steel and alloy spring steel, including tempered alloy steel, surface-hardened alloy steel (carburized steel, nitrided steel, surface high-frequency quenched steel, etc.), and alloy steel for cold plastic forming (steel for cold heading, steel for cold extrusion, etc.). According to the basic chemical composition series, it can be divided into Mn series steel, SiMn series steel, Cr series steel, CrMo series steel, CrNiMo series steel, Ni series steel, and B series steel, etc.

　　The carbon content (wc) of alloy structural steel is lower than that of carbon structural steel, generally in the range of 0.15% to 0.50%. In addition to carbon, it also contains one or more alloying elements, such as silicon, manganese, vanadium, titanium, boron, nickel, chromium, and molybdenum. Alloy structural steel is easy to harden and is not easily deformed or cracked, making it suitable for heat treatment to improve the steel's properties. Alloy structural steel is widely used in the manufacture of various transmission and fastening parts for automobiles, tractors, ships, steam turbines, and heavy machine tools. Low-carbon alloy steel is generally carburized, while medium-carbon alloy steel is generally tempered.

　　Alloy tool steel is medium-to-high carbon steel containing various alloying elements, such as silicon, chromium, tungsten, molybdenum, and vanadium. Alloy tool steel is easy to harden and is not prone to deformation or cracking, making it suitable for manufacturing large, complex-shaped cutting tools, molds, and measuring instruments. The carbon content of alloy tool steel varies depending on its application. Most alloy tool steel has a carbon content (wc) of 0.5% to 1.5%. Steel for hot deformation molds has a lower carbon content (wc) in the range of 0.3% to 0.6%; steel for cutting tools generally has a carbon content (wc) of around 1%; steel for cold working molds has a higher carbon content, such as graphite mold steel with a carbon content (wc) of 1.5%, and high-carbon, high-chromium cold working mold steel with a carbon content (wc) as high as 2% or more.

　　High-speed tool steel is high-carbon, high-alloy tool steel with a carbon content (wc) of 0.7% to 1.4%. It contains alloying elements that form high-hardness carbides, such as tungsten, molybdenum, chromium, and vanadium. High-speed tool steel has high red hardness; even at high-speed cutting temperatures of 500-600 degrees Celsius, its hardness does not decrease, ensuring good cutting performance.

　　Springs are used under impact, vibration, or long-term alternating stress, so spring steel requires high tensile strength, elastic limit, and high fatigue strength. In terms of processing, spring steel requires a certain hardenability, resistance to decarburization, and good surface quality. Carbon spring steel is high-quality carbon structural steel with a carbon content (wc) in the range of 0.6% to 0.9% (including normal and higher manganese content). Alloy spring steel is mainly silicon-manganese steel, with slightly lower carbon content, mainly relying on increased silicon content (wSi) (1.3% to 2.8%) to improve performance; there are also chromium, tungsten, and vanadium alloy spring steels. Combining China's resources and the requirements of new technologies in automobile and tractor design, new steel grades have been developed by adding boron, niobium, and molybdenum to silicon-manganese steel, extending the service life of springs and improving spring quality.

　　Bearing steel is used to manufacture rolling balls, rollers, and bearing rings. Because bearings operate under extreme pressure and friction, bearing steel requires high and uniform hardness and wear resistance, as well as a high elastic limit. The uniformity of the chemical composition, the content and distribution of non-metallic inclusions, and the distribution of carbides are all strictly required for bearing steel. Bearing steel is also known as high-carbon chromium steel, with a carbon content (wc) of around 1% and a chromium content (wc) of 0.5% to 1.65%. Bearing steels are divided into six categories: high-carbon chromium bearing steel, chromium-free bearing steel, carburized bearing steel, stainless bearing steel, medium-high temperature bearing steel, and non-magnetic bearing steel.

　　Electrical silicon steel is mainly used to manufacture electrical silicon steel sheets for the electrical industry. Silicon steel sheets are a very important type of steel in the manufacturing of motors and transformers. According to chemical composition, silicon steel can be divided into low-silicon steel and high-silicon steel. Low-silicon steel contains 1.0% to 2.5% silicon (wSi) and is mainly used for manufacturing motors; high-silicon steel contains 3.0% to 4.5% silicon (wSi) and is generally used for manufacturing transformers. Their carbon content (wc) is ≤0.06% to 0.08%.

　　Rail steel Rail steel mainly bears the pressure and impact load of locomotives and rolling stock, so it requires sufficient strength and hardness and a certain degree of toughness. The rail steel commonly used is carbon-killed steel smelted by open-hearth furnace and converter. This steel contains 0.6%~0.8% carbon (Wc), belonging to medium carbon steel and high carbon steel, but the manganese content (WMn) is higher, in the range of 0.6%~1.1%. Ordinary low-alloy steel rails have been widely used, such as high-silicon rails, medium-manganese rails, copper-containing rails, and titanium-containing rails. Ordinary low-alloy steel rails are more wear-resistant and corrosion-resistant than carbon steel rails, and their service life is greatly improved.

　　Steel for shipbuilding Steel for shipbuilding refers to steel used to manufacture the hull structures of seagoing vessels and large inland river vessels. Because hull structures are generally manufactured using welding methods, shipbuilding steel is required to have good weldability. In addition, it is also required to have certain strength, toughness, and certain low-temperature and corrosion resistance. In the past, low-carbon steel was mainly used as shipbuilding steel. Ordinary low-alloy steel has been widely used, with existing steel grades such as 12 manganese ship steel, 16 manganese ship steel, and 15 manganese vanadium ship steel. These steel grades have comprehensive characteristics such as high strength, good toughness, easy processing and welding, and seawater corrosion resistance, and can be successfully used to manufacture 10,000-ton ocean-going giants.

　　Steel for bridges Railway or highway bridges bear the impact load of vehicles, so the bridge steel requires certain strength, toughness, and good fatigue resistance, and the surface quality of the steel is also required to be high. Bridge steel often uses alkaline open-hearth killed steel, and ordinary low-alloy steels such as 16Mn and 15MnVN have been successfully used.

　　Boiler steel Boiler steel mainly refers to the materials used to manufacture superheaters, main steam pipes, and the heating surfaces of boiler furnaces. The main performance requirements for boiler steel are good weldability, certain high-temperature strength, and resistance to alkali corrosion and oxidation. Commonly used boiler steel includes low-carbon killed steel smelted by open-hearth furnace or low-carbon steel smelted by electric furnace, with carbon content (Wc) in the range of 0.16%~0.26%. Pearlitic heat-resistant steel or austenitic heat-resistant steel is used in the manufacture of high-pressure boilers. Ordinary low-alloy steel is also used to build boilers, such as 12Mn, 15MnV, and 18MnMoNb.

　　Steel for welding rods This type of steel is specifically used for manufacturing arc welding and gas welding electrodes. The composition of the steel varies with the material being welded. According to the needs, it is roughly divided into three categories: carbon steel, alloy structural steel, and stainless steel. The sulfur and phosphorus content (Ws, Wp) of these steels is not more than 0.03%, which is stricter than that of general steel. These steels do not require mechanical properties, only chemical composition testing.

　　Stainless steel Stainless acid-resistant steel, referred to as stainless steel, is composed of two parts: stainless steel and acid-resistant steel. In short, steel that can resist atmospheric corrosion is called stainless steel, and steel that can resist chemical medium (such as acids) corrosion is called acid-resistant steel. Generally speaking, steel with a chromium content (Wcr) greater than 12% has the characteristics of stainless steel. According to the microstructure after heat treatment, stainless steel can be divided into five categories: ferritic stainless steel, martensitic stainless steel, austenitic stainless steel, austenitic-ferritic stainless steel, and precipitation-hardened stainless steel.

　　Heat-resistant steel Steel that has oxidation resistance, sufficient high-temperature strength, and good heat resistance under high-temperature conditions is called heat-resistant steel. Heat-resistant steel includes oxidation-resistant steel and heat-resistant steel. Oxidation-resistant steel is also called scaling-resistant steel. Heat-resistant steel refers to steel that has good oxidation resistance and high high-temperature strength at high temperatures. Heat-resistant steel is mainly used for parts that are used for a long time at high temperatures.

　　High-temperature alloy High-temperature alloy is a heat-resistant material that has sufficient long-term strength, creep strength, thermal fatigue strength, high-temperature toughness, and sufficient chemical stability at high temperatures, and is used for thermal power components operating under high-temperature conditions above 600 degrees Celsius. According to their basic chemical composition, they can be divided into nickel-based high-temperature alloys, iron-nickel-based high-temperature alloys, and cobalt-based high-temperature alloys.

　　Precision alloy Precision alloys are alloys with special physical properties. They are indispensable materials in the electrical industry, electronics industry, precision instrument industry, and automatic control systems. According to their different physical properties, precision alloys are divided into seven categories: soft magnetic alloys, deformable permanent magnetic alloys, elastic alloys, expansion alloys, thermal bimetals, resistance alloys, and thermocouple alloys. The vast majority of precision alloys are based on ferrous metals, and only a few are based on non-ferrous metals. Note: Wc, Ws, Wmn, Wp represent the mass fractions of C, S, Mn, P respectively.

　　Common Terminology

　　1. Standards: Standards are unified regulations for repetitive things and concepts. They are based on the comprehensive achievements of science, technology, and practical experience, agreed upon by relevant parties, approved by the competent authority, published in a specific form, and used as commonly observed rules and basis. The standards implemented for steel products in China include national standards (GB, GB/T), industry standards (YB), local standards, and enterprise standards. 2. Technical Conditions: The various performance indicators and quality requirements that a product should meet as stipulated in the standard are called technical conditions, such as chemical composition, external dimensions, surface quality, physical properties, mechanical properties, process properties, internal structure, delivery status, etc. 3. Assurance Conditions: According to the provisions of the technical conditions for metallic materials, the manufacturer should conduct inspections and ensure that the inspection results meet the specified requirements for performance, chemical composition, internal structure, and other quality indicators, which are called assurance conditions. 4. Quality Certificate: The production of metallic materials, like the production of other industrial products, is carried out according to unified standard regulations, implementing a product factory inspection system; unqualified metallic materials are not allowed to be delivered. For delivered metallic materials, the manufacturer provides a quality certificate to guarantee its quality. The quality certificate for metallic materials not only states the name, specifications, number of delivered items, weight, etc., of the material, but also provides all the inspection results of the specified guaranteed items. 5. Quality Certificate: The quality certificate is the supplier's confirmation and guarantee of the inspection results of this batch of products, and it is also the basis for the purchaser to conduct re-inspection and use. 5. Quality Grades: According to different requirements for steel surface quality, shape, and dimensional tolerances, steel quality is divided into several grades. For example, first-grade products and second-grade products. Sometimes different grades are formulated for a certain requirement. For example, for surface quality, it is divided into first-grade, second-grade, and third-grade; for surface decarburization depth, it is divided into group one, group two, etc., all indicating differences in quality. 6. Precision Grades: For some metallic materials, the standard specifies several dimensional tolerances, and according to the size of the dimensional tolerances, they are divided into several grades, called precision grades. Precision grades are divided into ordinary precision, higher precision, and high precision according to the tolerance. The higher the precision grade, the smaller the allowable dimensional deviation. When ordering, attention should be paid to writing the precision grade requirements into the contract and other relevant documents. 7. Grade: The grade of a metallic material is the name given to each specific metallic material. The grade of steel is also called the steel grade. The grades of metallic materials in China generally reflect the chemical composition. The grade not only indicates the specific variety of the metallic material, but also allows for a rough judgment of its quality. In this way, the grade conveniently provides a common concept of the quality of specific metallic materials, thus bringing great convenience to production, use, and management. 8. Variety: The variety of metallic materials refers to products with different uses, shapes, production processes, heat treatment states, and particle sizes. 9. Model: The model of a metallic material refers to the code used to represent different shapes and categories of profiles and cemented carbides, etc., using Chinese pinyin (or Latin) letters and one or more numbers. The number indicates the nominal size of the main part. 10. Specifications: Specifications refer to the different dimensions of metallic materials of the same variety or the same model. Generally, different dimensions have different tolerances. In product standards, the specifications of a variety are usually arranged in order from small to large. 11. Surface State: It is mainly divided into bright and non-bright. It is common in steel wire and steel strip standards, and the main difference lies in whether bright annealing or general annealing is adopted. Polishing, grinding, pickling, and plating are also considered as surface states. 12. Edge State: The edge state refers to whether the strip steel is trimmed. Trimmed ones are trimmed strip steel, and untrimmed ones are untrimmed strip steel. 13. Delivery State: The delivery state refers to the final plastic deformation processing or final heat treatment state of the product delivery. Those delivered without heat treatment include hot-rolled (forged) and cold-rolled states. Those treated with normalizing, annealing, high-temperature tempering, quenching and tempering, and solid solution are collectively called heat-treated delivery, or according to the heat treatment categories, they are respectively called normalized, annealed, high-temperature tempered, quenched and tempered, etc., delivery states. 14. Material Softness and Hardness: This refers to the different softness and hardness of the steel obtained by using different heat treatments or degrees of work hardening. In some strip steel standards, it is divided into extra-soft steel strip, soft steel strip, semi-soft steel strip, low-hardness steel strip, and hard steel strip. 15. Longitudinal and Transverse: The longitudinal and transverse directions mentioned in steel standards refer to the relative relationship with the rolling (forging) and drawing directions. Those parallel to the processing direction are called longitudinal; those perpendicular to the processing direction are called transverse. The sample taken along the processing direction is called the longitudinal sample; the sample taken perpendicular to the processing direction is called the transverse sample. The fracture on the longitudinal sample is perpendicular to the rolling direction, so it is called the transverse fracture; the fracture on the transverse sample is parallel to the processing direction, so it is called the longitudinal fracture. 16. Theoretical Weight and Actual Weight: These are two different methods for calculating the delivery weight. Delivery by theoretical weight is the delivery weight calculated according to the nominal dimensions and density of the material. Delivery by actual weight is the delivery weight obtained by weighing (weighbridge) the material. 17. Nominal Dimensions and Actual Dimensions: Nominal dimensions refer to the nominal dimensions specified in the standard, which are the ideal dimensions hoped to be obtained during production. However, in actual production, the actual dimensions of the steel are often larger or smaller than the nominal dimensions. The dimensions actually obtained are called actual dimensions. 18. Deviation and Tolerance: Because it is difficult to achieve nominal dimensions in actual production, the standard specifies an allowable difference between the actual dimensions and the nominal dimensions, which is called deviation. A negative difference is called a negative deviation, and a positive difference is called a positive deviation. The sum of the absolute values of the allowable positive and negative deviations specified in the standard is called the tolerance. Deviation has directionality, i.e., it is expressed as "positive" or "negative"; tolerance has no directionality. 19. Delivery Length: There are four types of regulations for steel delivery length in current standards:

　　Fixed length, and any steel whose length is within the range specified in the standard and has no fixed length is called the usual length. However, for the convenience of packaging, transportation, and measurement, when enterprises cut steel, it is best to cut it into several different lengths according to the situation, and strive to avoid irregular lengths.

　　Those with a short length of 20 are called short lengths. Refining method refers to the type of steelmaking furnace used, such as open-hearth furnace, electric arc furnace, electroslag furnace, vacuum induction furnace, and mixed steelmaking. The term "refining method" in the standard does not include deoxidation methods (such as fully deoxidized killed steel, semi-deoxidized semi-killed steel, and rimmed steel) and casting methods (such as top-pouring, bottom-pouring, and continuous casting). 2l Chemical composition (product composition) refers to the chemical composition of steel products, including the main components and impurity elements, with the content expressed as a weight percentage. 22 Melting composition The melting composition of steel refers to the chemical composition of the steel after melting (such as in-furnace deoxidation) is completed and during the mid-pouring stage. 23 Finished product composition The finished product composition of steel, also called verification analysis composition, refers to the chemical composition obtained by drilling or planing test samples from finished steel products according to the prescribed method (see GB/T222 for details) and analyzing them according to the prescribed standard methods. The finished product composition of steel is mainly used by users or inspection departments for the acceptance of steel. Production plants generally do not perform complete finished product analysis, but they should ensure that the finished product composition meets the standard requirements. For some major products, or sometimes due to certain reasons (such as process changes, unstable quality, melting composition close to the upper and lower limits, or failure to obtain melting analysis results), production plants also perform finished product composition analysis. 24 High-quality steel and high-grade high-quality steel (with the letter A) are also called quality steel and high-grade quality steel. The difference lies in that high-grade high-quality steel is superior to high-quality steel in some or all of the following aspects: ① Narrowing the carbon content range; ② Reducing the content of harmful impurities (mainly sulfur and phosphorus); ③ Ensuring higher purity (meaning less inclusion content); ④ Ensuring higher mechanical properties and processability. There are diverging opinions among large domestic steel companies regarding the future prospects of steel. Ansteel reduced its plate prices for April on March 18. Last week, Baosteel raised the futures prices of its major products for April. However, Wuhan Iron and Steel and Shougang did not follow Baosteel's lead for their main products, and even Shagang introduced a price reduction policy with subsidies.