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Ultra-thin oriented silicon steel at 0.08 mm has cleared expert appraisal in China. Furthermore, the panel rated the overall result as internationally leading. Until now, China imported roughly 3,000 tons of this sheet every year, worth over RMB 600 million. Consequently, ±800 kV UHVDC converter valves can now use domestic strip. At Jiangsu Zhongtong Weiye Special Steel Co., Ltd. in Wuxi, we supply CRGO coil, so this shift changes what buyers can specify.

Why 0.08 mm Ultra-Thin Oriented Silicon Steel Is So Hard

Goss texture must form inside a strip thinner than 0.10 mm. In practice, that leaves almost no room for grain-growth control. Rolling, high-temperature annealing, and coating all fight the same constraint. Of course, thinner strip also raises handling loss and surface-defect risk.

The project team mapped how Goss nuclei depend on stored-energy distribution. Subsequently, they identified the large-angle nucleation path for Goss grains. That insight opened a workable process window.

R&D Timeline: Five Phases to a 100-Ton Line

Phase 1 (Years 1–2) — basic theory. Researchers defined the stored-energy window that allows Goss nucleation in confined strip.

Phase 2 (Years 2–3) — base material. A magnesium-silicate-free bottom layer was developed for 0.23–0.30 mm high-induction grades. Therefore, the base sheet no longer relied on a glass film.

Phase 3 (Years 3–4) — coating. An inorganic heat-resistant coating replaced the conventional system. As a result, high-temperature annealing stopped damaging insulation.

Phase 4 (Year 4–5) — rolling. High-pressure-ratio rolling with one-time recrystallization replaced multi-pass schedules. Meanwhile, texture sharpness improved measurably.

Phase 5 (Year 5) — production. A 100-ton ultra-thin strip line started up. In addition, the team built matching iron cores for UHVDC valves.

The Results That Matter

• Strip gauge reached 0.08 mm.
• Core loss and magnetic induction both beat imported strip.
• Two ±800 kV UHVDC projects adopted the material.
• Converter valve localization rate rose to a new level.

Notably, the appraisal moved China’s high-end ultra-thin CRGO from zero to one. Before this, aerospace and defense buyers had no domestic option. Instead, they paid monopoly pricing on a 3,000-ton annual import base.

What This Means for Buyers

Gauge selection now spans a wide ladder:

• 0.08–0.10 mm: high-frequency transformers, aerospace, defense relays.
• 0.15–0.20 mm: EV traction motors, fast-charging transformers.
• 0.23–0.27 mm: UHV and UHVDC power transformers.
• 0.30–0.35 mm: distribution transformers, general cores.

Our standard stock covers 0.23–0.35 mm. M3 Grain Oriented Electrical Steel is our thinnest regular grade at 0.23 mm. Furthermore, M4 Grain Oriented Electrical Steel covers 0.27–0.30 mm cores. For rotating machines, M19 Non Oriented Electrical Steel serves 0.35–0.50 mm laminations.

Ultra-thin 0.08–0.10 mm stays tight in supply. Therefore, we quote those gauges case by case against mill allocation.

Supply Reality Check

Domestic output of ultra-thin CRGO still trails demand. Expect allocation rather than open stock for the thinnest gauges. However, standard grades ship freely from stock. In contrast, the bottleneck has shifted from technology to capacity ramp.

Frequently Asked Questions

What We Do Not Do

• We do not manufacture the 0.08 mm strip in-house.
• We do not build converter valves or transformers.
• We do not supply amorphous ribbon or nanocrystalline cores.

Consequently, we remain a sourcing and slitting partner, not a technology claimant.

Specify Your Order

1. State the gauge and grade.
2. Give slit width and coil ID.
3. Confirm tonnage and destination port.

We reply with stock, price, and lead time within one working day.

• Email: vera.liang@ztwysteel.com
• Location: Xishan District, Wuxi, Jiangsu, China
• Supply range: CRGO M3/M4/M5 at 0.23–0.35 mm, CRNGO M19–M43, ultra-thin on allocation
• Slitting tolerance: ±0.05 mm
• Documentation: MTC EN 10204 3.1, core loss per ASTM A343 / IEC 60404-2