Four varieties of steel -45# flat steel

Section steel is one of the four major types of steel (plate, tube, mold, silk). According to the section shape, section steel is divided into simple section steel.

Process method of 45# flat steel

Spring flat steel is made by converter smelting process. Compared with the existing technology, it has the following advantages and positive effects:

1. Smelting flat steel by converter mainly uses molten iron as raw material, there are fewer harmful elements in molten iron, and the quality of flat steel produced is guaranteed.

2. Because of the high yield, less power consumption, the cost per ton than the electric furnace drops.

3. The molten steel is cast into billet directly, which omits the billet process and reduces the cost.

4. High measuring rate of continuous casting billet can guarantee the measuring rate of flat steel and meet the needs of users.

classification

Ferrous, steel and non-ferrous metals

Before introducing the classification of steel, I will briefly introduce the basic concepts of ferrous metals, steel and non-ferrous metals.

1. Ferrous metals refer to iron and iron alloys. Such as steel, pig iron, iron alloy, cast iron and so on. Steel and pig iron are based on iron, with carbon as the main added element of the alloy, collectively known as iron-carbon alloy.

Pig iron refers to iron ore into a blast furnace smelting product, mainly used to make steel and castings.

Cast pig iron is smelted in a cupola to obtain cast iron (liquid), which is cast into castings. This kind of cast iron is called cast iron.

Ferroalloy is an alloy composed of iron and silicon, manganese, chromium, titanium and other elements. Ferroalloy is one of the raw materials of steelmaking. It is used as a deoxidizer and alloying element additive in steelmaking.

2. Put the pig iron in the steelmaking furnace and melt it according to a certain process, that is, steel is obtained.

3. Non-ferrous metals, also known as non-ferrous metals, refer to metals and alloys other than black metals, such as copper, tin, lead, zinc, aluminum, brass, bronze, aluminum alloy and bearing alloys. In addition, chromium, nickel, manganese, molybdenum, cobalt, vanadium, tungsten, titanium and so on are also used in the industry. These metals are mainly used as alloy additions to improve the performance of metals. Tungsten, titanium, molybdenum and so on are mostly used in the production of hard alloy for cutting tools. These nonferrous metals are called industrial metals. In addition, there are precious metals: platinum, gold, silver, and rare metals, including radioactive uranium and radium.

Classification of steel

Steel is an iron-carbon alloy with carbon content ranging from 0.04% to 2.3%. In order to ensure toughness and plasticity, the carbon content is generally no more than 1.7%. In addition to iron and carbon, the main elements of steel are silicon, manganese, sulfur, phosphorus, etc. There are a variety of classification methods for steel, and the main methods are as follows:

1. Classification by quality

(1) Ordinary steel (P≤0.045%, S≤0.050%)

(2) High quality steel (P, S ≤0.035%)

(3) High quality steel (P≤0.035%, S≤0.030%)

2. Classification by chemical composition

(1) medium carbon steel (C≤0.25-0.60%); High carbon steel (C≤0.60%).

(2) Alloy steel: low alloy steel (total alloying element content ≤5%); Medium alloy steel (total alloying element content > 5-10%); High alloy steel (total alloying element content > 10%).

3, according to the forming method classification:

(1) Forged steel

(2) Cast steel

(3) hot rolled steel

(4) cold drawn steel.

4. Classification by metallographic organization

(1) Annealed: hypoeutectoid steel (ferritic + pearlite); Eutectoid steel (pearlite); Eutectoid steel (pearlite + cementite); Leytenite steel (pearlite + cementite).

(2) normalizing: pearlite steel; Bainite steel; Martensitic steel; Austenitic steel.

(3) No phase transition or partial phase transition

5. Classification by use

(1) Steel for construction and engineering: ordinary carbon structural steel; Low alloy structural steel; Reinforcing steel.

(2) Structural steel

a. Steel for mechanical manufacturing: tempered structural steel; Surface hardening structural steel: including carburizing steel, ammoniating steel, surface hardening steel; Easy cutting structural steel; Cold plastic forming steel: including cold stamping steel, cold heading steel.

(4) Special performance steel: stainless acid-resistant steel; Heat-resistant steel: including anti-oxidation steel, heat-strong steel, valve steel; Electrothermal alloy steel; Wear-resistant steel; Low temperature steel; Steel for electrical purposes.

(5) Professional steel: such as bridge steel, ship steel, boiler steel, pressure vessel steel, agricultural machinery steel, etc.

6. Comprehensive classification

(1) Ordinary steel

a. Carbon structural steel: Q195; Q215(A, B); Q235(A, B, C); Q255(A, B); Q275.

b. Low alloy structural steel

c. Ordinary structural steel for specific purposes

(2) High quality steel (including high quality steel)

a. Structural steel: high-quality carbon structural steel

b. Tool steel: carbon tool steel; Alloy tool steel; High speed tool steel.

c. Steel with special properties: stainless steel and acid-resistant steel; Heat-resistant steel; Electrothermal alloy steel; Electrical steel; High manganese wear resistant steel.

7. Classification by smelting method

(1) According to the furnace type

a. Open hearth steel: acid open hearth steel; Basic open hearth steel.

b. Converter steel: acid converter steel; Basic converter steel. Or bottom-blown converter steel; Side-blown converter steel; Top blow converter steel.

c. Electric furnace steel: electric arc furnace steel; Electroslag furnace steel; Induction furnace steel; Vacuum consumable furnace steel; Electron beam furnace steel.