Surface Treatment Technologies for Hot Rolled Steel Coils

Introduction

Hot rolled steel coils are important intermediate products in steel plate production, widely used in industries such as construction, shipbuilding, and machinery manufacturing. However, the surfaces of hot rolled steel coils often have defects such as oxide scales, scale pits, and scratches, which affect their appearance and performance. These defects can lead to a decrease in the strength, plasticity, and weldability of the steel, and make it more susceptible to corrosion. Therefore, surface treatment of hot rolled steel coils is essential.

Oxide Scale Removal Techniques

Oxide scale is the main defect on the surface of hot rolled steel coils, which can reduce the strength, plasticity, and weldability of the steel. Therefore, it must be removed before subsequent processing.

Common oxide scale removal techniques include:

Pickling: Using acidic solutions to dissolve oxide scale, which is one of the most commonly used methods. The advantage is high efficiency and low cost. The disadvantage is the generation of acidic wastewater, causing environmental pollution. Read more: Common Defects and Control Measures in Pickled Plates

Alkaline cleaning: Using alkaline solutions to dissolve oxide scale, with less environmental pollution. The advantage is high safety and minimal environmental pollution. The disadvantage is relatively low efficiency and higher cost.

Shot blasting: Using high-speed steel shots to impact the surface of the steel to remove oxide scale. The advantage is high efficiency and the ability to remove stubborn oxide scale. The disadvantage is that it can cause damage to the surface of the steel.

Rust removal by jetting: Using high-pressure water or air jets to impact the surface of the steel to remove oxide scale. The advantage is that it does not damage the surface of the steel. The disadvantage is relatively low efficiency and higher cost.

Hot Rolled Steel Coils

Surface Finishing Techniques

Surface finishing techniques for hot rolled steel coils can improve the surface quality and appearance of the steel, as well as enhance its processing and usability.

Common surface finishing techniques include:

Cold rolling: Smoothing the surface of the steel through cold rolling. The advantage is obtaining a high-precision surface. The disadvantage is that it may reduce the strength and plasticity of the steel.

Annealing: Making the surface of the steel soft through annealing. The advantage is improving the processing performance of the steel. The disadvantage is that it may reduce the strength of the steel.

Polishing: Making the surface of the steel shiny like a mirror through polishing. The advantage is achieving a good appearance. The disadvantage is higher cost.

Wire drawing: Making the surface of the steel present a uniform texture through wire drawing. The advantage is improving the wear resistance of the steel. The disadvantage is that it may reduce the smoothness of the steel.

Protective Coating Technologies

Protective coating technologies can protect the surface of hot rolled steel coils from corrosion and extend their service life.

Common protective coating technologies include:

Galvanizing: Coating the surface of the steel with a layer of zinc, which can effectively prevent corrosion. The advantage is low cost and good corrosion resistance. The disadvantage is that it may reduce the weldability of the steel. View Galvanized Sheet Steel Coil

Aluminum coating: Coating the surface of the steel with a layer of aluminum, which has good corrosion resistance and heat resistance. The advantage is good corrosion resistance and heat resistance. The disadvantage is higher cost. View Galvalume Steel Coil

Painting: Coating the surface of the steel with a layer of paint to prevent corrosion and improve appearance. The advantage is obtaining various colors and appearances. The disadvantage is relatively poor durability.

Conclusion

Surface treatment technologies for hot rolled steel coils are key technologies to improve the quality and performance of steel. Users can choose appropriate surface treatment technologies according to their actual needs. Contact us for more.