1. Q: Is cold-rolled coil suitable for manufacturing server racks and cabinets? What are its main advantages?
A: Absolutely. Cold-rolled coil is the mainstream base material for server racks and cabinets, accounting for over 70% of the market share. Its main advantages include:
High surface smoothness: The cold-rolling process ensures a thickness accuracy of ±0.05mm, resulting in a smooth surface that can be directly sprayed or coated, meeting the appearance requirements of server racks;
Good formability: It can meet complex processing needs such as bending, punching, and stretching, making it suitable for components such as rack doors, side panels, and frames;
Adjustable strength: A range of materials, from ordinary mild steel (DC01) to high-strength steel (HC340LA), can be selected to meet different load-bearing requirements;
Controllable cost: Compared to stainless steel and aluminum, the raw material cost of cold-rolled coil is 30%~50% lower, making it the most cost-effective choice for industrial server racks;
Strong coating adaptability: After phosphating and electrostatic spraying, it can withstand salt spray tests for over 500 hours, meeting the protection requirements for indoor and outdoor server racks.
2. Q: How to select cold-rolled coils for server racks and enclosures? What are the differences between different parts?
A: Material selection should be based on the type of rack and its location:
Application | Recommended Grade | Thickness Range | Key Requirements
Outdoor Server Rack Shell | DC01 + Galvanized Coating (or SECC) | 1.2~2.0mm | Corrosion resistance preferred, galvanized coating ≥80g/m², salt spray test ≥480 hours
Indoor Server Rack | DC01/DC03 | 1.5~2.5mm | Balances load-bearing capacity and appearance, FD grade surface coating, no orange peel finish after spraying
Industrial Control Cabinet | DC01/SPCC | 1.2~2.0mm | High bending precision, 90° bend inner angle R≤0.5t, no cracks
3. Q: How should surface treatment be adapted when manufacturing cabinets from cold-rolled coils?
A: Bare cold-rolled coils are prone to corrosion and must undergo surface treatment. Common solutions are as follows:
Electrostatic powder coating (mainstream solution): The process flow is degreasing → phosphating → spraying → curing. The phosphating film weight is controlled at 2~5g/m², and the coating thickness is 60~80μm. It passes the cross-cut adhesion test (level 0) and salt spray test (≥500 hours).
Lamination/film application: Used for high appearance requirements (such as medical equipment cabinets). PVC or PET film is applied to the surface of the cold-rolled sheet, providing both decorative appeal and scratch resistance.
Electro-galvanizing (SECC): Used for high corrosion resistance applications. The coating is uniform, and the corrosion resistance at the cut edges is better than hot-dip galvanizing, but the cost is higher.
Passivation treatment: Used for internal non-exterior parts. It provides short-term rust prevention and is the lowest cost, but the corrosion resistance is limited (only applicable to dry environments).
Key control point: The surface roughness of cold-rolled coils needs to be controlled within Ra 0.8~1.5μm. Too low a roughness will affect the coating adhesion, while too high a roughness will result in a large amount of paint consumption.
4. Q: What problems are commonly encountered in the processing of cold-rolled coils for chassis and cabinets? How to solve them?
A: Common problems and solutions:
Problem Type | Manifestation | Cause Analysis | Solution
Bending Cracking | 90° bend outer corner crack | Insufficient material elongation, bending radius too small | Replace DC01 with DC03/DC04; inner bending angle R≥1.0t
Excessive Springback | Angle deviation after bending >2° | High yield strength of high-strength steel, improper die clearance | Reserve springback compensation angle when using HC340LA; adopt bottom bending process
Punching Burrs | Burrs on hole edge >0.1mm | Excessive die clearance, poor material shearing performance | Control die clearance to 8%~12% of plate thickness; select DC03 with better ductility
Orange Peel/Underlying Coating | Uneven coating surface, local uncoated areas | Surface oil residue, uneven phosphating | Strengthen degreasing process; control phosphating film uniformity
5. Question: How does the cost-effectiveness of cold-rolled coil in making server racks compare to galvanized sheet and stainless steel?
Indoor Standard Cabinets: Cold-rolled coils with powder coating are preferred, offering the best cost-performance ratio and the lowest overall cost.
Outdoor Standard Cabinets: Hot-dip galvanized steel sheets are recommended, requiring no powder coating or only a topcoat, balancing corrosion resistance and economy.
High-end/Export Cabinets: SECC or cold-rolled coils with high-performance powder coating can be used, ensuring a salt spray test duration of ≥1000 hours.
For harsh corrosive environments: 304 stainless steel is recommended, but this will increase costs by 2-3 times.