Q235 is a very common ordinary carbon structural steel, and its yield strength is stable at about 235MPa. It is one of the most widely used steels and plays an important role in many industrial and civil fields. It has good comprehensive mechanical properties, including certain strength, good plasticity and toughness, and can withstand certain tensile, compression and bending loads. At the same time, it also has good welding performance, and is not prone to welding defects, pores, cracks, etc. It also has good cutting performance, cold bending and hot bending performance. For example, the steel frame keel used on some construction sites is made by cold bending. Q235 can be divided into four types according to its chemical composition: Q235A, Q235B, Q235C, and Q235D. Do you know the difference between these four materials?

Features of Q235A: Q235A has the highest carbon content, about 0.14% to 0.22%, sulfur ≤0.050, phosphorus ≤0.045, moderate strength, good plasticity and toughness, good welding performance, and easy processing and forming. For example, in some occasions where the strength requirements are not extremely high, such as non-critical supporting parts in building structures, Q235A steel can be easily made into the required shape through processes such as bending and stamping. Application scenarios: Widely used in the construction industry, used to make various building components, such as steel beams, steel columns, roof trusses, etc. In general mechanical manufacturing, it is also used to make some parts that are not subjected to much force, such as small brackets, housings, etc. At the same time, it is also used in the manufacture of daily necessities, such as some simple metal furniture frames.

Features of Q235B: The carbon content of Q235B is about 0.12% to 0.20%, sulfur ≤0.045, and phosphorus ≤0.045. Compared with Q235A, it is more stable in quality. The sulfur and phosphorus content is more strictly controlled, and it performs well in toughness and impact resistance. For example, in a low temperature environment, the toughness reduction of Q235B is smaller than that of Q235A, and it can withstand a certain degree of impact without prone to brittle fracture. Application scenarios: commonly used in building structures and mechanical parts with high requirements for safety and reliability. In chemical equipment manufacturing, it is used to make some storage containers, etc. In bridge construction, it is also a commonly used type of steel, which can withstand the impact of dynamic loads such as vehicle driving.

Q235C features: The carbon content of Q235C is about ≤0.18%, sulfur ≤0.040, and phosphorus ≤0.040. It has stricter control over chemical composition and performance. It has good low-temperature impact toughness and can maintain good mechanical properties under low temperature conditions. And there are more stringent requirements in process links such as rolling. Application scenarios: Mainly used in occasions with high requirements for low-temperature toughness. It is often used in building structures and mechanical equipment in cold northern regions. It can keep the equipment in good performance in low-temperature environments and ensure safe and reliable operation.

Q235D features: The carbon content of Q235D is about ≤0.17%, sulfur ≤0.035, and phosphorus ≤0.035. It is the highest quality grade in the Q235 series. It has a low carbon content and the most stringent restrictions on harmful impurities such as sulfur and phosphorus. It has excellent low-temperature toughness and fatigue resistance. Its production process is complex and the quality inspection standards are high, which can ensure that the steel still maintains good performance under harsh environmental conditions (such as low temperature, high humidity, high corrosion, etc.). Application scenarios: It is often used to manufacture important structures and equipment with extremely high quality and safety requirements. For example, in offshore oil platforms, large buildings in high-cold areas, special machinery and other fields, Q235D can effectively resist adverse factors such as seawater corrosion and extremely low temperatures, ensuring the long-term stable operation of equipment.