Insulation basis
Insulation basis
Grain oriented electrical steel strip is supplied with a thin in- organic coating on the glass film layer formed during annealing. A film thickness of 2 to 5 µm provides good electrical resistance and a high stacking factor.
The coating, which is annealing resistant up to 840 °C, enables wound cores and sheet blanks to be stress relief annealed. The coating is chemically resistant to liquids to which it is typi-cally exposed during the production process and has no effect on the various types of transformer oils.
We offer two types of insulation coatings: the chromium-contain-ing coating and the chromium-free coating. Both coatings are similar from a technological point of view.
| COLORATION | |
|---|---|
| Color deviations are possible, but they have no influence on the properties | Phosphate on glas film: gray |
| COATING | |
|---|---|
| Coated sides | both sides |
| Coating thickness | 2 µm - 5 µm |
| SURFACE INSULATION RESISTANCE | |
|---|---|
| at room temperatureaccording to IEC 60404-11 | > 10 Ω cm2 |
| ANNEALING RESISTANCE | |
|---|---|
| Under inert gas according to IEC 60404-12 | 840 °C / 2 h |
| DESIGNATION | |
|---|---|
| Comparison with the designations IEC 60404-1-1 | EC-5-G on EC-2 |
| Comparison with the designations ASTM A976 | C-5 over C-2 |
| CHEMICAL RESISTANCE | |
|---|---|
| w.r.t. transformer oil | very good |