Q235 AF What is it?

Q235-AF indicates Grade A boiling steel.

As a common carbon structural steel, the specific situation of Q235-AF is as follows:

1. Q represents the yield limit of this material, 235 represents the yield value of this material is about 235MPa, with the increase of the thickness of the material, its yield value will decrease, due to the moderate carbon content and good comprehensive performance, strength, plasticity and welding properties are well matched, and the most widely used.

2. The quality of grade A is poor, and the impact toughness test is not required.

3. F represents boiling steel, as a kind of steel with incomplete deoxidation, poor plasticity and toughness, welded structures made of this material, joints are prone to cracks when subjected to dynamic load, and it is not suitable to work at low temperatures, and sometimes hardening will occur.

Extended Materials. Q235-AF.

It is understood that high-quality carbon structural steel is different from Q235-AF, an ordinary carbon structural steel, and the expression method is number + (element symbol) + (deoxidation method symbol) + (special purpose symbol), the specific details are as follows:

1. The two digits at the beginning of the steel number indicate the carbon content of the steel, which is expressed in a few ten-thousandths of the average carbon content, for example, the average carbon content of the steel, the steel number is "45", note that this is different from the sequence number, so it cannot be read as 45 steel.

2. For high-quality carbon structural steel with high manganese content, manganese elements should be marked, such as 50mn.

3. Boiling steel, semi-calm steel and high-quality carbon structural steel for special purposes should be specially marked at the end of the steel number, for example, semi-calm steel with an average carbon content and a steel grade of 10b.

q235-af

To put it bluntly, it is carbon steel, Q: yield point, 235: represents the yield point value, A:

It is a quality grade, divided into A, B, C D, and four types. f: It is a deoxidation method.

There are mainly f: boiling steel, b: semi-calm steel, z:

Calming steel, TZ: special sedative steel.

That's all, if you don't understand, let's ask again. Everyone has to learn.

Q235A is carbon structural steel.

Q235 indicates carbon structural steel with a yield point of 235MPa. If necessary, the steel number can be followed by a symbol indicating the quality grade and the method of deoxidation. The quality grade symbols are A, B, C, which means that there is no impact, B is above 20 degrees, C is above 0 degrees, D is above -20 degrees, and the difference between A and D refers to the difference in impact temperature in their performance.

They are: Q235A, which is not required for impact toughness test; Q235B grade, which is used for room temperature (20) impact toughness test; Q235C grade, is for 0 impact toughness test; Q235D grade, is for -20 impact toughness test.

Q235A has good toughness and plasticity, has a certain elongation, and has good welding performance and thermal workability. Q235A is generally used in the hot rolling state, and the rolled sections, steel bars, steel plates, and steel pipes can be used to manufacture various welded structural parts, bridges and some ordinary machine parts, such as bolts, tie rods, rivets, collars and connecting rods.

Because the electrons of metals tend to detach, they have good electrical conductivity, and metal elements are usually positive in compounds, but when the temperature is higher, the resistance will increase because of the thermal ** hindrance of the nucleus. The bonds between metal molecules are metallic bonds, so they can be re-established by changing positions at will, which is why metals have good stretchability.

In nature, the vast majority of metals exist in a chemical state, and a few metals such as gold, silver, platinum, and bismuth exist in a free state. Most of the metal minerals are oxides and sulfides, and other forms are chlorides, sulfates, carbonates and silicates.

The above content reference: Encyclopedia - Carbon Structural Steel.

Grade Q235A

China ISC U12352

Other names: Q235AZ

Old grade A3

Corresponds to standard GB T 700-2006

Carbon structural steel.

Carbon structural steels are classified as carbon steels.

Performance: Ease of machinability, Weldability.

Tags: Calming Steel, Quality Grade A Carbon Structural Steel.

Description Good plasticity, toughness, welding performance, cold stamping performance, as well as certain strength, good cold bending performance, suitable for steel structure and reinforced concrete structural steel requirements.

User examples: widely used in the manufacture of thin plates, steel bars, steel structures with various section steel, building structures, bridges, machine bases, mechanical parts, carburizing or carbonitriding parts, weldments, brackets, tie rods, connecting rods, pins, shafts, screws, nuts, ferrules, etc.

This standard is suitable for use in general delivery conditions, and is usually used for welding, riveting, bolting hot-rolled steel plates, steel strips, sections and steel rods for engineering structures.

Grade suffix letters: A, B, C, D indicate quality grade.

f--boiling steel; z--sedative steel; TZ - Special Calming Steel.

In the representation of the composition of the grade, the Z and Z symbols can be omitted without <>

Q235A metal is generally solid at room temperature, with metallic luster, most of which are excellent conductors of electricity and heat, malleable, dense, and have a high melting point. The earth's metal resources are widely found in the earth's crust and oceans, except for a few very inactive metals such as gold and silver, which exist in elemental forms, the rest exist in the form of chemical compounds. Metals are widely present in nature, and are extremely common in life, and are very important and most widely used in modern industry.

For ordinary carbon structural steel, Q represents the yield of this material, and the 235 behind it refers to the yield value of this material. Q235 means that the yield point is 235MPa, and A represents the steel of grade A quality. There are four types: A, B, C, and D, which represent the mass fraction of sulfur and phosphorus content.

Grade C and D have the lowest quality score, ***.