Eco-friendly
Eco-friendly chromium-free coated hot-dip galvannealed steel
Products with low pollution
With reference to RoHS 2011/65/EU Annex II and its revised directive (EU) 2015/863, the third-party testing institutions accredited by TAF (Taiwan Accreditation Foundation) use the IEC 62321-7-1 method to analyze hexavalent chromium and other hazardous substances. The third-party testing institution tested the samples and chemicals of "chromium-free passivated galvannealed steel sheet" and "chromium passivated galvannealed steel sheet" respectively. The results confirmed that no hexavalent chromium or other harmful substances were detected in the chromium-free galvannealed steel sheet and its solution. This indicates that the eco-friendly process of chromium-free galvannealed steel coils not only meets product quality requirements, but also has the advantage of protecting the environment and meets the environmental demands of "low-pollution products".
Test reports of chromium-free passivated galvanized iron alloy steel coils
Test Report I Test Report II
The ability to extend the life time
Compared with chromium passivated hot-dip galvannealed steel sheet, chromium-free passivated hot-dip galvannealed steel sheet has good corrosion resistance and has a longer life time. Our company conducts 75~480 hours of neutral salt spray test according to CNS8886/ASTM B-117 standard, and conducts surface corrosion grade evaluation according to ASTM D610 to observe the percentage of rust area produced by "chromium-free passivated galvannealed steel sheet" and "chromium passivated galvannealed steel sheet" over a long period of time. After a 480-hour salt spray test, it was found that chromium-free passivated galvannealed steel sheet produced white rust and red rust later than chromium passivated galvannealed steel sheet, which is sufficient to prove that "chromium-free passivated galvannealed steel sheet" has a longer life time.
According to the table below, it can be seen that under the salt spray test, it takes 240 to 360 hours for chromium-free passivated hot-dip galvannealed steel sheet to produce red rust. Compared with chromium passivated hot-dip galvannealed steel sheet which red rust occurs in 120 to 168 hours, it indicates that the chromium-free passivated hot-dip galvannealed steel sheet has a longer life time. For detailed test reports, please refer to Appendix 2-1 to 2-3.
According to literature, a one-year and six-month exposure test in a harsh environment (such as Naoetsu, Japan) is roughly equivalent to a 24-hour salt spray test (Appendix 3-1). Based on a conservative estimate, the 24-hour salt spray test is roughly equivalent to one year of atmospheric exposure test. The life time of the chromium-free passivated hot-dip galvannealed steel sheet is longer about 5 to 8 years than that of chromium passivated hot-dip galvannealed steel sheets, meeting the environmental protection needs of "extended the life time."
| chromium passivated galvannealed steel sheet(C2GA) | chromium-free passivated galvannealed steel sheet(G6GA) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Salt water spray time(hour) | 75 | 120 | 168 | 240 | 360 | 480 | 75 | 120 | 168 | 240 | 360 | 480 |
| Rust Level (Test 1) | 9 | 4* | 3* | 0* | 0* | 0* | 9 | 9 | 5 | 0* | 0* | 0* |
| Rust Level (Test 2) | 8 | 8 | 4* | 2* | 0* | 0* | 9 | 9 | 8 | 6 | 0* | 0* |
| Rust Level (Test 3) | 6 | 7 | 4 | 2* | 0* | 0* | 9 | 9 | 8 | 5 | 0* | 0* |
| Note | Due to the edge effect, areas within 10mm of the edge are not included in the assessment of corrosion resistance;〔*〕indicates red rust. | |||||||||||
Reference data: (Salt spray test for 24 hours is approximately equivalent to one year and six months of atmospheric exposure test)
Reference