Welcome to Zhishang Steel Co., Ltd.
TEL: (Gavin) +86-15665898999 | Email : info@zhishangsteel.com
First, modern production line process analysis
1. Pre-treatment of key processes
Alkali wash degreasing: The NaOH solution of pH12.5 is used to remove 5-8g/m² of rolling oil
Reduction annealing: Heating to 720-850 ° C in H₂+N₂ atmosphere to eliminate work hardening
Zinc liquid composition: Modern production line adopts Zn-0.2% al-0.03mg formula, which improves fluidity by 15%
2. Coating control technology
The air knife system accurately controls the zinc layer thickness through 0.3-0.5MPa air pressure, and the error is controlled within ±3g/m². Wisco CGL production line adopts double air knife design to achieve single-sided differential thickness coating (such as 20/10g/m²).
2. Prevention and control of common quality defects
1. Surface defect map
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Zinc scar: Zinc slag particle size > 0.5mm need to replace the zinc pan
White rust: When the storage humidity is > 70%, the ZnO oxide layer is produced within 72 hours
2. Mechanical properties control
Automobile plate requires yield strength ≥140MPa, elongation ≥34%. Edge wave defects are eliminated by in-line tension straightening (elongation 0.5-1.5%). The 1200MPa galvanized sheet developed by Hangang has been commercialized.
ABOUT USOverviewThe company mainly deals in color-coated, galvanized, stainless steel pipes, stainless steel coils, stainless steel plates of various materials; hot-rolled series of rebar, medium and heavy plates, coils, I-beams, angle steels, channel steels, H-beams and other steel products and deep processing Service. (The company’s annual invent···