The high frequency welded(hfw) H Beam is a commonly used structural steel material, widely applied in construction and bridge engineering.
Most builders now use HFW H-section due to its many benefits, such as strong stability, good bending resistance, environmental friendliness, and lightness. It is particularly valuable in earthquakes, where its strong bending resistance makes buildings more stable and reduces losses.
Other advantages include:
①High section size accuracy
Made from high-quality steel coils, the shape accuracy after welding is excellent, facilitating structural assembly. Custom section sizes can be produced according to user requirements.
②Superior section performance
The ratio of flange to web thickness can be increased compared to rolled steel, providing better bending resistance and higher section performance at the same weight.
③Lighter weight
For the same bending performance, components can be made lighter; for the same section performance, components are lighter.
③Uniform metallographic structure at the welding site
The materials of the web and flanges are evenly fused.
(2)Disadvantages
①Poor corrosion resistance
HFW H beam has weak corrosion resistance. When rusted, its performance significantly decreases, which can lead to building collapses and casualties. In humid or acidic environments, rusting is more severe, shortening the lifespan of the steel.
Chemical and electrochemical corrosion are the main causes of H-beam corrosion. To prevent this, applying anti-corrosion coatings can slow down the corrosion process and extend the lifespan of HFW H beam.
②Poor heat resistance
Its heat resistance is weak, and at high temperatures, the strength and plasticity of HFW H-shaped steel decrease, becoming more severe with higher temperatures until it fails. To improve heat resistance, fire-resistant coatings and heat-resistant materials can be added.
When processing HFW H beam, it is essential to follow relevant standards to ensure product quality and engineering safety.
(1)Material standards
Choose the appropriate H-shaped steel material based on design requirements and strictly follow national or industry standards to ensure the material's mechanical properties and chemical composition meet requirements.
(2)Process standards
Conduct high-frequency welding operations according to relevant regulations, controlling parameters such as preheating temperature, welding current, and welding speed to ensure the quality of the weld meets standard requirements.
(3)Quality standards
Rigorously inspect the welded H-shaped steel for quality, including appearance, size tolerance, and weld quality, to ensure the product meets standard requirements.
Additionally, standards for HFW H-shaped steel also involve acceptance specifications. During construction, the steel must be accepted according to standards, including visual inspection, size measurement, and weld inspection. Only after passing strict acceptance procedures can the product be used to ensure project quality and safety.
Safety regulations are also part of the HFW H-shaped steel standards. During high-frequency welding operations, safety procedures must be strictly followed, including protective measures for welding personnel and safety requirements for the working environment.
Control of current frequency is crucial during welding, as higher frequencies result in faster welding speeds and smaller heat-affected zones, leading to smoother welds.Power control is important; it should not be too high to avoid burning or too low to prevent weak welding, which can waste materials.
When welding special plates, ensure proper alignment and smooth transition between plates. If there are un-melted welding defects in thicker areas, it can significantly affect the quality of the component. The main measure is to weld the seam in a sloped shape, with a maximum slope ratio of 1:2.5.
Quality can be improved by:
1. Advantages and Disadvantages of HFW H-Shaped Steel
(1)AdvantagesMost builders now use HFW H-section due to its many benefits, such as strong stability, good bending resistance, environmental friendliness, and lightness. It is particularly valuable in earthquakes, where its strong bending resistance makes buildings more stable and reduces losses.
Other advantages include:
①High section size accuracy
Made from high-quality steel coils, the shape accuracy after welding is excellent, facilitating structural assembly. Custom section sizes can be produced according to user requirements.
②Superior section performance
The ratio of flange to web thickness can be increased compared to rolled steel, providing better bending resistance and higher section performance at the same weight.
③Lighter weight
For the same bending performance, components can be made lighter; for the same section performance, components are lighter.
③Uniform metallographic structure at the welding site
The materials of the web and flanges are evenly fused.
(2)Disadvantages
①Poor corrosion resistance
HFW H beam has weak corrosion resistance. When rusted, its performance significantly decreases, which can lead to building collapses and casualties. In humid or acidic environments, rusting is more severe, shortening the lifespan of the steel.
Chemical and electrochemical corrosion are the main causes of H-beam corrosion. To prevent this, applying anti-corrosion coatings can slow down the corrosion process and extend the lifespan of HFW H beam.
②Poor heat resistance
Its heat resistance is weak, and at high temperatures, the strength and plasticity of HFW H-shaped steel decrease, becoming more severe with higher temperatures until it fails. To improve heat resistance, fire-resistant coatings and heat-resistant materials can be added.
2. Standards for HFW H-shaped Steel
When processing HFW H beam, it is essential to follow relevant standards to ensure product quality and engineering safety.(1)Material standards
Choose the appropriate H-shaped steel material based on design requirements and strictly follow national or industry standards to ensure the material's mechanical properties and chemical composition meet requirements.
(2)Process standards
Conduct high-frequency welding operations according to relevant regulations, controlling parameters such as preheating temperature, welding current, and welding speed to ensure the quality of the weld meets standard requirements.
(3)Quality standards
Rigorously inspect the welded H-shaped steel for quality, including appearance, size tolerance, and weld quality, to ensure the product meets standard requirements.
Additionally, standards for HFW H-shaped steel also involve acceptance specifications. During construction, the steel must be accepted according to standards, including visual inspection, size measurement, and weld inspection. Only after passing strict acceptance procedures can the product be used to ensure project quality and safety.
Safety regulations are also part of the HFW H-shaped steel standards. During high-frequency welding operations, safety procedures must be strictly followed, including protective measures for welding personnel and safety requirements for the working environment.
3. Precautions for High-Frequency Welding of H-Profile
Control of current frequency is crucial during welding, as higher frequencies result in faster welding speeds and smaller heat-affected zones, leading to smoother welds.Power control is important; it should not be too high to avoid burning or too low to prevent weak welding, which can waste materials.When welding special plates, ensure proper alignment and smooth transition between plates. If there are un-melted welding defects in thicker areas, it can significantly affect the quality of the component. The main measure is to weld the seam in a sloped shape, with a maximum slope ratio of 1:2.5.
4. Quality Control Measures for HFW H-shaped Steel
Quality can be improved by:
- Using high-quality raw materials and avoiding inferior products.
- Paying attention to small details in the welding process and regularly inspecting and maintaining welding equipment.
- Training operators to improve their skills, establishing correct production rules, and guiding workers to follow them.
- Introducing advanced production equipment and technology.
