Introduction
High-quality carbon structural steel (GB 699-88) is a type of steel material with a carbon content of 0.20-0.35%, also known as high-quality carbon steel or carbon structural steel. It mainly contains carbon and small amounts of silicon, manganese and sulfur. High-quality carbon structural steel is relatively soft and easy to form, but because of its higher strength and better hardenability, it is generally used under medium or high-load conditions, such as shaft and gear, excellent medium gear, and important components of machines and vehicles.
Properties and Classification
High-quality carbon structural steel (GB 699-88) has excellent mechanical properties. With low intensity, low cost and good weldability, it is widely used in building industry and light industry. High-quality carbon structural steel (GB 699-88) also has high strength and good toughness, especially for cold processing and welding. After quenching and tempering, high-quality carbon structural steel will have excellent fatigue strength and large bearing capacity.
High-quality carbon structural steel (GB 699-88) is divided into five levels according to its yield strength, intensity and impact toughness. The corresponding grades are Q195 (195 Mpa), Q235 (235 Mpa), Q275 (275 Mpa), Q345 (345 Mpa) and Q420 (420 Mpa). Different grades have different levels of mechanical properties, which have a certain impact on their application.
Application
High-quality carbon structural steel (GB 699-88) is widely used in various industries, such as aircraft, automotive, jewelry, bicycles, ships, agricultural machinery and mining machinery, etc. It is also used to make bridges, frames, tanks, chimneys and other parts.
High-quality carbon structural steel (GB 699-88) can be made into several kinds of steel products, such as rolled steel plate (for use to make shipbuilding plate and container plate), high-strength steel plate, bridge steel plate, pressure vessel plate, all kinds of pipe fittings and other products.
Manufacturing Process
The manufacturing process of high-quality carbon structural steel (GB 699-88) involves several steps, such as melting, ingot casting, hot rolling and heat treatment.
Firstly, melting: melting of high-quality carbon structural steel (GB 699-88) involves two steps. The first step is to smelt the metal melt in electric arc furnace (EAF) with electric energy to reach the required temperature.Then, steel ingots are cast in the converter for further processing.
The next step is hot rolling, which is to roll the steel ingots into hot metal sheets. These sheets are further processed through cold rolling and annealing technology so that the metal can achieve certain mechanical properties such as strength and ductility.
Finally, heat treatment is used to improve the properties of high-quality carbon structural steel (GB 699-88). Heat treatment can include quenching, tempering and normalizing. Quenching and tempering can change the hardness and strength of the steel, while normalizing can improve the impact toughness of the steel.
Conclusion
High-quality carbon structural steel (GB 699-88) is an important type of steel material with a carbon content of 0.20-0.35%, which has excellent mechanical properties and is widely used in many industries. It has low intensity, low cost and good weldability and is suitable for cold processing and welding. High-quality carbon structural steel can be divided into five levels according to its yield strength and is used to make various kinds of steel products. In addition, the manufacturing process of high-quality carbon structural steel involves melting, hot rolling, and heat treatment.
