The Q235 steel material is in accordance with PRC standards. Carbon steel for special projects and purposes, like marine and bridge steel, typically uses carbon structural steel expression. However, the letter indicating intents and purposes is included at the end of steel grade.
Table of Contents
Q235 is a plain carbon structural steel that is used throughout China. It is also known as Q235A, Q235B, Q235C, and Q235D. Since it is mild steel, it is utilized in production without heat treatment. The Q designates the yield point, and the 235 indicates the yield strength. It has good plasticity and weldability.
Q235 is a plain carbon structural steel that is used throughout China. It is also known as Q235A, Q235B, Q235C, and Q235D. Since it is mild steel, it is utilized in production without heat treatment. The Q designates the yield point, and the 235 indicates the yield strength. It has good plasticity and weldability.
Q235 Equivalent Materials
The Q235 steel can be substituted with equivalent materials that include A36 USA ASTM, Q235 China GB/T, and SS400 Vietnam/Japanese JIS.
Characteristics of Q235
As the thickness of the material increases, Q235’s yield value decreases. Due to its moderate carbon content, the performance is comprehensive and adequate. Q235 also matches well in strength, welding, and plasticity. Most often, it is rolled into a steel plate, rod, bar, or angle frame. It is most commonly used in the engineering and construction industries.
Q235 Equivalent Materials
The Q235 steel can be substituted with equivalent materials that include A36 USA ASTM, Q235 China GB/T, and SS400 Vietnam/Japanese JIS.
Characteristics of Q235
As the thickness of the material increases, Q235’s yield value decreases. Due to its moderate carbon content, the performance is comprehensive and adequate. Q235 also matches well in strength, welding, and plasticity. Most often, it is rolled into a steel plate, rod, bar, or angle frame. It is most commonly used in the engineering and construction industries.
The Q235 steel material is in accordance with PRC standards. Carbon steel for special projects and purposes, like marine and bridge steel, typically uses carbon structural steel expression. However, the letter indicating intents and purposes is included at the end of steel grade.
While the Q235 grade steel plate has lower mechanical properties than the A36 materials, these materials can generally be substituted for one another, as long as there are no special requirements and needs involved. If only for the material’s mechanical properties, it is generally acknowledged that Q235 and A36 are similar to those of high-quality carbon structural steel.
Chemical composition of Q235
Q235 is divided into four levels: A, B, C, D| Grade | C | Mn | Si | S | P |
|---|---|---|---|---|---|
| Q235A | ≤0.22% | ≤1.4% | ≤0.35% | ≤0.050 | ≤0.045 |
| Q235B | ≤0.20% | ≤1.4% | ≤0.35% | ≤0.045 | ≤0.045 |
| Q235C | ≤0.17% | ≤1.4% | ≤0.35% | ≤0.040 | ≤0.040 |
| Q235D | ≤0.17% | ≤1.4% | ≤0.35% | ≤0.035 | ≤0.035 |
Physical Properties of Q235
| Physical Properties | Metric | US/Imperial |
|---|---|---|
| Density | 7.85 g/cc | 0.284 lb/in³ |
Mechanical properties of Q235
| Mechanical Properties | Metric | US/Imperial |
|---|---|---|
| Tensile Strength, Ultimate | 400 – 550 MPa | – |
| Tensile Strength, Yield | 250 MPa | – |
| Elongation at Break | 0.2 | 0.2 |
| 0.23 | 0.23 | |
| Modulus of Elasticity | 200 GPa | 29000 ksi |
| Compressive Yield Strength | 152 MPa | 22000 psi |
| Bulk Modulus | 160 GPa | 23200 ksi |
| Poissons Ratio | 0.26 | 0.26 |
| Shear Modulus | 79.3 GPa | 11500 ksi |
Q235A level is not required for impact toughness test,
Q235B grade is used for impact toughness test at room temperature (20°℃).
Q235C grade is for 0°℃ impact toughness test,
Q235D grade is used for the -20℃ impact toughness test.
The impact toughness test uses Charpy ∨-shaped notched specimens. The impact toughness index is AKV.
For the above-mentioned grades B, C, and D steels, they are required to reach AKV≥27J under their respective temperature requirements. Therefore, the four ranks are ranked as A
Application of Q235
Because q235 has good welding performance, good plasticity, toughness, and certain strength, it is often rolled into thin plates, steel bars, welded steel pipes, etc., used in bridges, buildings, and other structures and the manufacture of ordinary screws, nuts, and other parts. And Q235 C and Q235 D grade steel can also be used as some professional steel.
Not only does Q235 possess toughness, weldability, and excellent plasticity, it retains strength while offering outstanding cold-bending performance. It is perfect for welded structures, including factory buildings, steel bars, towers, boilers, bridges, containers, vehicles, and more. Q235 can also be used as mechanical parts, such as stands, stressed rods, nuts, connecting rods, brackets, and other components. Q235 and varying grades of steel plates can be cut to specification.
Q235 Vs SS400 Vs A36
Chinese standard Q235, the tensile strength is 370~500 MPa, and the yield strength is 235MPa.
Japanese standard SS400, the tensile strength is 400~510 MPa, and the yield strength is 245Mpa.
American Standard A36, the tensile strength is 58~80 Ksi (about 400~550MPa), and the yield strength is 36 Ksi (about 250MPa).
Because the mechanical properties of these three grades are similar, they can be replaced within a certain range.
Heat Treatment
235 belongs to low-carbon structural steel with a carbon content of about 0.12%-0.2%, which is equivalent to ordinary 10 and 20 steel. The hardness does not change much after quenching.
Q235 is generally bought without heat treatment. Generally, it is used in places where a large amount of steel is needed in engineering. The quantity is huge. Generally, it is used after hot rolling. Hot rolling is also a heat treatment of normalizing.
There are several reasons for not heat treatment,
- These occasions do not require too high mechanical requirements.
- The volume of these steel components is too large, and the heat treatment is difficult.
- These steels are often used for welding. After heat treatment, the heat treatment of the weld will be destroyed during the welding process.
- The material is cheap, the quality requirement is relatively low, and it is low-carbon steel, and the heat treatment effect is not good.
- If you have to use Q235 to quench the hardness, you can only carburize, and the cost is too high.
What Are The Different Grades Of Steel?
1. Classified by quality
Ordinary steel (P≤0.045%, S≤0.050%), high-quality steel (P and S ≤0.035%), and high-grade high-quality steel (P≤0.035%, S≤0.030%).
2. Classified by chemical composition
Carbon steel:
Low-carbon steel (C≤0.25%). Medium-carbon steel (0.25≤C≤0.60%) and high-carbon steel (C≥0.60%).
Alloy steel:
low alloy steel (total content of alloying elements ≤5%), medium alloy steel (total content of alloying elements>5~10%), high-alloy steel (total content of alloying elements>10%).
3. Classified by forming method:
Forged steel, cast steel, hot-rolled steel, cold-rolled steel.
The Difference Between Q235 and Q345
Q235 and Q345 are two grades of Chinese steel commonly used in construction and engineering projects. Although they have similar chemical compositions, there are differences in their mechanical properties and applications.
The main differences between Q235 and Q345 are as follows:
- Chemical Composition: Both Q235 and Q345 are carbon structural steels, but Q345 contains additions of several elements like manganese, silicon, and trace amounts of other alloying elements, whereas Q235 only has carbon and manganese.
- Tensile Strength: The tensile strength of Q345 is higher than that of Q235, which is why it is used for applications that require higher strength and load-bearing capacity.
- Yield Strength: The yield strength of Q345 is also higher than that of Q235, making it more durable and resistant to deformation under stress.
- Application: Q235 is commonly used in construction and engineering projects where low-strength materials are required, such as building components and basic structural components. On the other hand, Q345 is used in various applications that require higher strength and load-bearing capacity, such as bridges, steel structures, and heavy machinery.
In summary, Q235 and Q345 are two grades of Chinese steel with similar chemical compositions, but differ in their mechanical properties and applications. While Q235 is commonly used in low-strength applications, Q345 is typically used in high-strength applications that require greater load-bearing capacity.