1. Production Line Introduction: Hot dip (or hot) galvanizing is the processing technique to dip the pretreated base substance of carbon steel into melted liquefied zinc to obtain a protective zinc coat. Due to its good anticorrosion performance, galvanized plate is vastly applied into the industries of home appliance, decoration, advertisement, and civil construction, etc. Particularly, the home appliance industry (outer shell of air conditioner, outer plate of refrigerator, outer shells of washing machine, computer, and microwave oven, etc) has large demands on galvanized and color coated plates. According to the traditional methodology, galvanization can be sorted into United States Steel Corp and Sendzimir 2 methods. The main machineries process is as the following: manually coiler feeding — Ⅰ# & Ⅱ# uncoilers — Ⅰ# 2-roller pinching machine — shear 1 — Ⅱ# 2-roller piching machine — shear 2 — Ⅲ# 2-roller pinching machine — welding machine — Ⅰ# tensioning machine — Ⅰ# stocking looper — Ⅱ# tensional machine— pre-degreasing — roller brushing machine — electrolyzed degreasing — roller brushing machine — Ⅰ# water washing — roller brushing machine — Ⅱ# water washing — Ⅲ# water washing — Ⅰ# air blowing device — Ⅲ# tensing machine — tension testing roller — preheating furnace — heating furnace — soaking furnace — furnace throat — cooling furnace — hot tension roller — furnace note — zinc pot — sink roller — air knife — small zinc spangle device — condensing tower — 1st bending roller — horizontal cooling equipment — bending centering machine — vertical cooling equipment — hardening bath — hot air drying blower — Ⅳ# tensioning machine — skin roller machine — straightness rectifying machine — Ⅴ# tensioning machine — spraying chrome — electrical heating dryer — Ⅱ#stocking looper — Ⅵ# tensioning machine — spaying oiling machine — shear — Ⅳ# 2-rooler pinching machine — recoiler— coiler unloading manually. 2. Brief Introduction to Continuously Hot-dip Aluminum-Zinc-Silicon Coating Line: Hot dipped aluminum-zinc steel plate is called Galvalume (or GL plate), which is hot coated with an alloy of aluminum (AI 55%), zinc (Zn 43.5%) and silicon (Si 1.5%) on the surface. Due to a nature of steel matrix composite, it has an excellent performance of anticorrosion. Besides the excellent features of anticorrosion against atmosphere and heat resistance anti-oxidation bringing by aluminum coating, GL plate also has the advantage of eminent chemical and electrical protectiveness granted by galvanization. The main characteristics are: Smooth surface with an excellent anticorrosion ability again atmosphere, the anticorrosion life is 2-6 times of that of common hot-dip galvanized steel plate; l Good heat resisting anti-oxidation performance. When exposed to a circumstance of 300℃ temperature for a long period, the color will not fade. Even can be sorted for a long duration at a high temperature of 500℃~600℃. Have good abilities of waterproof and soil anticorrosion. Moreover, its heat reflectivity is higher than 75%, more applicable to low temperature inner liner of furnace to reduce heat transmission of furnace wall; Good easiness of being color coated and machined, high combination capability with organic compounds, is a good base material for organic color coated steel strip. The machining and welding characters are similar to those of hot-dip galvanized plate, can be machined by cold bending or punching, the finished product is with a good appearance; l The density of aluminum is lighter then zinc, for which sake, the coating density of aluminum– zinc alloy is only 3.7kg/dm, is the most popular technique at present. |
3. Typical Modes
No. 1 |
Type: |
1450 hot dip continuous galvanizing |
Specifications |
Raw material: Cold rolling coiler; Thickness: 0 . 2~ 1.2mm Width: 700~ 1250mm Coiler weight: 25t Coating thickness: 60~ 280g /m 2 |
Parameters : |
Max speed: 180m /min Annual yield: 150,000 tons |
Features: |
1: so mature technology, and easy control processing; 2: small investment; 3: low temperature requirement of steel strip when passing through zinc pot |
Remarks: |
United States Steel Corp method |
No. 2 |
Type: |
1450 hot dip continuous aluminum-zinc plating |
Specifications |
Raw material: Cold rolling coiler; Thickness: 0 . 2~ 1.2mm Width: 700~ 1250mm Coiler weight: 25t Coating thickness: 40~ 200g /m 2 |
Parameters : |
Max speed: 180m /min Annual yield: 150,000 tons |
Features: |
1, strict cleaning requirement on base belt surface; 2, high temperature requirement of steel belt when entering zinc pot; 3, fast cooling down requested after plating; 4, large investment, and difficult to control the process; 5, skin roller required; |
Remarks: |
United States Steel Corp method |
No. 3 |
Type: |
800 hot dip continuous galvanizing |
Specifications |
Raw material: Cold rolling coiler, or hot rolled acid pickling coiler; Thickness: . 5~ 3.5mm (or 0.5~ 1.5mm ) Width: 400~ 650mm Coiler weight: 10t Coating thickness: 40~ 200g /m 2 |
Parameters : |
Max speed: 55m /min (or 100m /min ) Annual yield: 120,000 tons |
Features: |
1, small investment, small footprint; 2,easy production management; 3, direct heating and regenerative burning modes adopted, saving energy; 4, no pretreatment section, save the investment and maintenance cost; 5, low production cost and stable product quality; |
Remarks: |
Sendzimir method |
No. 4 |
Type: |
650 hot dip continuous galvanizing |
Specifications |
Raw material: Cold rolling coiler, or hot rolled acid pickling coiler; Thickness: . 5~ 3.5mm (or 0.5~ 1.5mm ) Width: 200~ 450mm Coiler weight: 7t Coating thickness: 40~ 200g /m 2 |
Parameters : |
Max speed: 60m /min (or 100m /min ) Annual yield: 100,000 tons |
Features: |
1, small investment, small footprint; 2, easy production management; 3, direct heating and regenerative burning modes adopted, saving energy; 4, no pretreatment section, save the investment and maintenance cost; 5, low production cost and stable product quality; |
Remarks: |
Sendzimir method |
|
4. Product and Service Supplying Scope: Turn-key project contractor, including pre-sale consulting, project planning, process/equipment designing, machinery manufacturing, complete production line installing, equipment commissioning, technique process prescription, operator training, production assisting, post-sale service, and value added service. In response to various requirements of clients, sufficient mature optimized professional solutions will be definitely proposed. We, JJRS, are always willing to respond your inquiries at anytime and in anywhere. |