1.What are the core properties of DC05 galvanized coil?
The material standard of DC05 is derived from the European EN 10130 standard (corresponding to the "cold-rolled steel sheet for deep drawing" in the domestic GB/T 5213 standard). It is an "advanced deep-drawing grade" among cold-rolled steel sheets (with better formability than DC01/DC03/DC04). The complete marking of the galvanized product is usually "DC05+Z" (Z stands for hot-dip galvanizing; if it is electro-galvanized, it is marked as "DC05+ZE").
2.What is the zinc coating type and protection level of DC05?
Hot-dip galvanizing (DC05+Z): The zinc coating thickness is typically 50-275 g/m² (on both sides, such as Z60, Z100, and Z275, where the number represents the total weight of the zinc coating on both sides). The zinc layer is metallurgically bonded to the substrate, resulting in strong corrosion resistance (up to 500-1000 hours in a neutral salt spray test). This method is suitable for stamping parts used in outdoor or humid environments (such as appliance exterior components).
Electrogalvanizing (DC05+ZE): The zinc coating thickness is thinner (typically 10-50 g/m², such as ZE10 and ZE20), resulting in a smoother and flatter surface (roughness Ra ≤ 1.0 μm). However, its corrosion resistance is weaker than hot-dip galvanizing and requires an additional passivation layer (such as chromium passivation or chromium-free passivation). This method is suitable for precision indoor parts (such as electronic component housings).
3.Why choose DC05 galvanized coil?
Ultimate deep-drawing performance: The baseplate's low yield strength and high elongation enable it to handle complex curved surface drawing (such as deep-cavity stamping of appliance linings and three-dimensional forming of automotive parts). It is less susceptible to defects such as cracking, wrinkling, and necking, reducing stamping scrap rates.
Excellent surface quality: DC05 baseplates typically have a surface grade of "FB" (no visible defects) or "FC" (minor defects permitted but covered by paint). After galvanizing, they maintain a low roughness (hot-dip galvanizing Ra ≤ 2.5μm, electroplated galvanizing Ra ≤ 1.0μm), making them suitable for bare parts or directly painted parts requiring high aesthetic requirements (no additional polishing required).
Stable mechanical consistency: The steel mill uses a "continuous annealing process" to control the grain size and texture of DC05 baseplates, ensuring minimal fluctuation in mechanical properties (yield strength fluctuation ≤ 10 MPa) within the same batch and coil, preventing dimensional deviations caused by uneven material properties during stamping. Balancing protection and processability: The zinc layer provides basic rust resistance (5-10 times higher than cold-rolled sheet corrosion resistance) without significantly sacrificing the plasticity of the substrate, resolving the contradiction between "high protection" and "easy processability" (some ordinary galvanized coils are prone to zinc layer shedding during stamping due to excessively thick zinc layer or excessively hard substrate).
4.What is the production process of DC05 galvanized coil?
Base Plate Rolling (Cold Rolling): Using hot-rolled coil as raw material, the base plate undergoes multiple cold rolling passes (reduction ratio 40%-60%) to the target thickness (usually 0.3-2.0mm). Recrystallization annealing is then performed in a continuous annealing furnace (temperature 700-800°C) to eliminate cold rolling internal stress, resulting in a DC05 base plate with low hardness and high plasticity.
Galvanizing:
Hot-dip galvanizing: The base plate undergoes "degreasing → pickling → reduction annealing (850-900°C) → zinc bath immersion (zinc bath temperature 450-460°C) → air knife purging (to control zinc layer thickness)" to form a uniform zinc-iron alloy layer followed by a pure zinc layer.
Electrogalvanizing: The base plate undergoes "degreasing → pickling → electroplating bath (zinc ion electrolytic deposition) → passivation treatment." The zinc layer thickness is precisely controlled by current density and plating time, resulting in a more refined surface. Finishing and post-processing: After galvanizing, the plate shape is corrected (to reduce warping) through a "stretching and leveling machine". Some products require "smoothing" (to improve surface smoothness) or "passivation" (to enhance corrosion resistance). Finally, they are coiled and packaged.
5.What are the typical application areas of DC05 galvanized coils?
Home Appliance Industry (Core Application Areas)
Precision components for white goods: such as refrigerator liners (deep-cavity stretch forming to avoid cracking), washing machine drums (a lower-cost alternative to stainless steel), and air conditioner evaporator covers (thinned stamping requiring high flatness).
Small appliance housings/components: such as microwave oven liners, electric kettle bases (complex curved surface stamping), and coffee machine water tanks (require rust resistance and food contact, some requiring food contact certification).
Automotive Industry (Mid- to High-End Components)
Automotive interior parts: such as instrument panel brackets, door trim panels, and seat adjustment components (require deep drawing with low springback to ensure assembly accuracy).
Small automotive exterior parts: such as rearview mirror brackets and wiper bases (hot-dip galvanizing DC05+Z, combining rust resistance and stampability, replacing some cold-rolled steel sheets with post-painting).
Electronics and Light Industry
Electronic equipment housings: such as router housings and printer consumables boxes (electrogalvanizing DC05+ZE, smooth surface, ready for direct screen printing or spray coating). Precision hardware: such as lock panels, lighter casings, and small tool housings (requiring complex stamping and flawless appearance).
Other special applications
Medical device accessories: such as small medical device casings (requiring low impurities, high surface quality, and some must meet medical-grade environmental standards).
Home hardware: such as high-end drawer slides and cabinet hinge components (requiring dimensional stability after stamping and basic rust resistance).