The feature of the galvalume steel strip:
-surface of the galvalume steel strip: Big spangle, normal spangle, small spangle.
-the thickness of the galvalume steel strip: 0.18-3.0mm
-the tolarance of the galvalume steel strip: -0.02-0mm for the thickness.
-the advantage for the galvalume steel strip: Instead of the galvanized steel strip, more beautiful than galvanized steel strip, but can be used for longer time than galvanized steel strip.
Specification:
1. Production Grade: SGCC, DX51D, Q195
2. Thickness: 0.18-1.5mm
3. Width: 914mm, 1000mm, 1200mm, 1250mm mainly
4. Coating Type: 55%Al, 43.5%Zn and 1.5%Si
5. Coating Thickness (both side, g/sqm): 50-150
6. Surface Finish: Regular Spangle, Small Spangle
7. Surface Treatment: Oring or Anti-finger print
8. Inside diameters: 508mm
9. Outside diameters: As per customers' requirements
Production procedure:
Aluminium-zinc alloy armor plate, is called Al-Zn coated plate for short Strips, after through three processes, including payoff reel, crop shear and welding, enter into the continuous annealing furnace.
During the annealing process, strips are heated closer to the recrystallizing temperature, and then heated to 20~50º C above the recrystallizing temperature in the reducing furnace. After keeping the same temperature for 170s, strips are naturally cooled to the normal temperature in the slow cooling process.
Afterward, strips enter into the zinc pot through the elephant's trunk and begin in the hot-dip coating process. The optimum temperature range of the plating coat is 630º C~660º C. Coated with aluminium-zinc alloy, strips enter into the cooling tower by the steady roll and air knife.
After fast cooled with wind or water, they are directly produced into Al-Zn armor plates. The general rate of cooling is 30º C/s or so, and strips are cooled to about 60º C.