The popularization of several types of knowledge about steel structure

There are four types of common steel structures, which are carbon steel structure, high strength, low alloy steel structure, carbon steel structure and alloy steel structure and special performance steel structure. What are the characteristics and functions of these different types of steel structures? What's the difference between them?

1. Carbon steel structure

Carbon steel frame is a kind of carbon steel. The carbon content is about 0.05%, 0.70%, and some can reach 0.90%. Can be divided into ordinary carbon steel frame and carbon steel frame two. There are many uses and lots of uses. It is mainly used in railway, bridge and various construction projects to manufacture all kinds of metal parts under static load, as well as small mechanical parts and general welding parts without heat treatment. Carbon steel structure is a large and extensive type of steel, accounting for about 70% of steel production.

2. High strength, low alloy steel structure

Low-alloy steel is a common alloy steel containing a small amount of alloying elements (the total amount of alloying elements is generally not more than 3%), which has the advantages of high strength (so-called high-strength low-alloy ordinary steel), good comprehensive performance, corrosion resistance, resistance to medium temperature, low temperature, processing performance, welding performance and other special properties.

3. carbon steel structure and alloy steel structure

Carbon steel structure is pure, less impurities, good mechanical properties. Can be used after heat treatment, according to the manganese content can be divided into ordinary manganese content (less than 0.80%) and high manganese content (0.80%1.20%) two categories, carbon content is less than 0.25%, usually used directly without heat treatment, or by carburizing, carburizing and other processes into gear, shaft, piston pin, etc.. Medium and small, carbon content of 0.25% and 0.60%, typical steel, 40, 45, 40Mn, 45Mn, etc., generally tempered into various mechanical parts and fasteners, carbon content of more than 0.60%, such as 65, 70, 85, 65Mn, 70Mn, etc., mainly used as spring steel, according to the carbon steel structure, A steel containing an appropriate amount of one or more alloying elements becomes an alloy steel structure. With suitable hardenability, metal after proper heat treatment, the microstructure of uniform of sorbitol, bainite and fine pearlitic, therefore has higher tensile strength and the performance is better than (average 0.85), high toughness and fatigue strength and lower ductile and brittle transition temperature, can be used in the manufacture of large cross section size of mechanical parts.

4. Special performance steel

Steel refers to a special performance with special physical and chemical properties of the steel, commonly used is stainless steel, heat-resistant steel and wear resistant steel, stainless steel is to point to have high resistance to corrosion of steel in corrosive medium, depending on the alloy elements, often using nickel chromium and chromium stainless steel stainless steel, heat-resistant steel is to point to have good oxidation resistance and high temperature resistance of steel, heat-resistant steel has two kinds: rust steel and heat resistant steel. Wear-resistant steel refers to steel with high wear resistance. Carbon content ranged from 1.0% to 1.3% and manganese from 11% to 14%. Because of the high manganese content, it is also known as high manganese steel.