Steel sheet, aluminium-silicon alloy-coated by the continuous hot-dip process, of commercial and drawing qualities
1Key Takeaways
This document is applicable to the minimum requirements for steel sheet, in coils and cut lengths, metallic-coated by the continuous hot-dip process, with aluminium-silicon alloy coating. The product is intended for heat-resisting applications and also where both corrosion and heat resistance are required. The steel sh…
2Expert Interpretation
An in-depth interpretation of the ISO 5000:2019 international standard's technical requirements for hot-dip aluminum-silicon alloy coated steel plates, covering core indicators such as chemical composition, mechanical properties, and coating quality. It is a professional guide for heat-resistant and corrosion-resistant industrial application scenarios.
Analysis of the core content of the standard
Aluminum-silicon alloy coated steel plate is suitable for commercial and stamping grade products produced by continuous hot dip coating process according to ISO 5000:2019 standard. The standard specifies the technical requirements for steel plates in the range of 0.4-3.0mm thickness, mainly for industrial applications that require both heat resistance and corrosion resistance.
Material property requirements
| Base material quality grade | Carbon content(max) | Tensile strength(MPa) | Elongation(min) |
|---|---|---|---|
| Commercial grade(01) | 0.15% | - | - |
| Stamping grade(02) | 0.10% | 430 | 30% |
| Deep drawing grade(05) | 0.02% | 380 | 38% |
Application case: The automobile exhaust system adopts AS120 coating grade aluminum-silicon alloy coated steel plate. Its 5-11% silicon content can withstand 800℃ high temperature environment, and the coating quality of 120g/m² meets the 10-year anti-corrosion requirements.
Key technical indicators of coating
The standard specifies 8 coating grades (AS040-AS300), including:
- Minimum value of triple spot test: 40-300g/m²
- Allowable deviation of single point test: not less than 75% of the standard value
- Bending test requirements: 1-3 times the plate thickness bending diameter without coating peeling
Conversion relationship:100g/m² coating mass ≈ 0.033mm coating thickness
Implementation suggestions
- The thickness marking method should be clearly specified when ordering (substrate alone or with coating)
- For stamping processing, it is recommended to select IF steel substrate with r value ≥1.4
- The welding process needs to adjust parameters for thick coating (>AS150)
- Keep dry during storage to avoid rust caused by wet storage
Technology evolution analysis
Compared with the 2011 version of the standard, the 2019 version has the following major updates:
- Refine the chemical composition requirements for interstitial-free steel (IF steel)
- Supplement the acceptance criteria for poorly thick coatings
- Optimize the specimen preparation method for mechanical properties testing