What is DC04ED Enameling Steel?
If you need extra deep drawing capability combined with direct-on (one-coat) enameling and enhanced dent resistance, DC04ED is the specialized grade you should consider.
DC04ED is a cold-rolled low carbon steel specifically optimized for direct-on enameling process (ED suffix) with stamping level 04 (extra deep drawing). Through decarburization annealing, it achieves extra-low carbon (≤0.004%), enabling excellent enamel adhesion directly to the steel surface without a ground coat. It also offers enhanced dent resistance for anti-denting applications and superior extra deep drawability for complex shapes.
When you use DC04ED, you benefit from the cost savings of one-coat enameling, excellent formability for complex parts, consistent surface quality after firing, and minimal rejects due to fish scaling or poor adhesion. It is also suitable for traditional two-coat enameling processes.
Typical applications include direct-on enameled water heater tanks, complex sanitary ware, bathtubs, household enamelware, industrial components, and extra deep drawn anti-denting applications.
According to GB/T 13790—2025 Cold rolled low carbon steel sheet and strip for vitreous enamelling Supersedes GB/T 13790—2008 / GB/T 29515—2013
Technical Data Sheet — Grade DC04ED (Direct-On Enameling Process / Extra Deep Drawing Quality / Decarburization Annealed)
📌 Designation System Clause 4.2
DC04ED consists of four parts:
- D — Steel flat product for cold forming
- C — Cold rolled condition
- 04 — Stamping level: Extra deep drawing (Level 04)
- ED — Enamelling type: Suitable for direct-on (one-coat) enameling process and anti-denting requirements; also suitable for traditional enameling
📖 Note: "ED" suffix indicates direct-on enameling process with enhanced dent resistance. DC04ED is decarburization annealed to achieve extra-low carbon (≤0.004%) for excellent enamel adhesion without a ground coat, with extra deep drawing capability.
📊 DC04ED vs Other Enameling Grades – Why Choose DC04ED?
1️⃣ vs DC04EK
DC04EK: Traditional enameling (C ≤0.06%)
DC04ED: Direct-on enameling + Anti-denting
Carbon: ≤0.004% (decarburization annealed) vs ≤0.06%
Enhanced dent resistance for anti-denting applications
Suitable for one-coat enameling process
2️⃣ vs DC03ED
DC03ED: Deep drawing (ReL ≤280/260/240 MPa)
DC04ED: Extra deep drawing (ReL ≤250/230/210 MPa)
Higher elongation (≥34-38% vs ≥30-34%)
Better formability for complex parts
3️⃣ vs DC06ED
DC06ED: Extra ultra deep drawing + Ti (C ≤0.008%)
DC04ED: Cost-effective extra deep drawing for direct-on enameling
Lower cost alternative without Ti addition
Both offer direct-on enameling capability
4️⃣ Key Advantages
- Extra-low carbon (≤0.004%) via decarburization annealing
- Direct-on (one-coat) enameling capability
- Enhanced dent resistance for anti-denting applications
- Extra deep drawability (stamping level 04)
- Higher elongation (≥38% for t>0.70mm)
- No stretcher strains for FC/FD within 6 months
- Hydrogen permeation validated (TH ≥6.7)
💡 Key takeaway: DC04ED is specifically designed for direct-on (one-coat) enameling processes with enhanced dent resistance and extra deep drawing capability. Its extra-low carbon content (≤0.004%) achieved through decarburization annealing enables excellent enamel adhesion without a ground coat, saving production costs while providing superior formability for complex parts.
🏺 Enameling Performance
🎯 Designed for
- Direct-on (one-coat) enameling
- Anti-denting applications
- Traditional two-coat enameling (also suitable)
- Complex extra deep drawn components
✨ Key Characteristics
- Excellent enamel adhesion (extra-low carbon)
- Proven fish-scale resistance (TH ≥6.7)
- Enhanced dent resistance
- Decarburization annealed (C ≤0.004%)
- Extra deep drawing capability
⚙️ What makes DC04ED a specialized direct-on enameling steel? Its extra-low carbon content (≤0.004%) achieved through decarburization annealing enables excellent enamel adhesion directly to the steel surface without a ground coat. The hydrogen permeation test validates fish scale resistance (TH ≥6.7 min/mm²), while enhanced dent resistance makes it suitable for anti-denting applications. With extra deep drawing capability (stamping level 04) and higher elongation (up to 38%), it handles complex part shapes without cracking.
⚙️ Chemical Composition Clause 7.1 – Table 5 (Ladle analysis, after decarburization annealing)
| Grade | C (%) | Mn (%) | P (%) | S (%) | Als (%) | Ti (%) |
|---|---|---|---|---|---|---|
| DC04ED | ≤0.004 | ≤0.40 | ≤0.025 | ≤0.050 | — | — |
🔬 Permissible deviations for product analysis according to GB/T 222 (Clause 7.1.2). Extra-low carbon (≤0.004%) achieved through decarburization annealing enables direct-on enameling without a ground coat. Low manganese (≤0.40%) provides excellent extra deep drawability.
📊 Mechanical Properties Clause 7.2 – Table 6
✅ Guarantee period: 6 months from manufacture date (7.2.1).
⚠️ Aging effect: yield & tensile strength may increase over time, elongation decreases – recommend early use (7.2.2).
⚠️ Aging effect: yield & tensile strength may increase over time, elongation decreases – recommend early use (7.2.2).
| Grade | ReL (MPa) ≤0.50mm |
ReL (MPa) >0.50~0.70 |
ReL (MPa) >0.70mm |
Rm (MPa) | A80mm (%) ≤0.50mm |
A80mm (%) >0.50~0.70 |
A80mm (%) >0.70mm |
|---|---|---|---|---|---|---|---|
| DC04ED | ≤250 | ≤230 | ≤210 | 270~350 | ≥34 | ≥36 | ≥38 |
📐 When yield phenomenon not obvious, use Rp0.2. 🔧 Lower yield strength limit of 140 MPa negotiable. 🧪 P6 transverse specimen. For thickness ≥1.5mm, yield strength upper limit is 225 MPa. Enhanced dent resistance for anti-denting applications.
📏 Stretcher Strain Clause 7.3 – Table 7
| Grade | Stretcher strain requirements |
|---|---|
| DC04ED (and DC01EK, DC03EK, DC04EK, DC05EK, DC03ED) | ✔️ For surface quality levels FC and FD, under room temperature storage, no stretcher strains within 6 months from manufacture date. |
| DC06EK, DC07EK, DC06ED | No stretcher strains shall appear under room temperature storage. |
📋 Enamelability Requirements Clauses 7.1.2 – 7.4.3
- 7.1.2 – Permissible deviations for product chemical analysis shall comply with GB/T 222.
- 7.2.1 – Mechanical properties guaranteed for 6 months from manufacture date as per Table 6.
- 7.2.2 – Due to aging effects, properties may change over time; early use is recommended.
- 7.3.1 – Skin-passing is applied, but stretcher strain tendency may reappear; recommend prompt use.
- 7.3.2 / Table 7 – For surface quality FC/FD, no stretcher strains within 6 months under room temperature storage.
- 7.4.1 – Hydrogen permeation test may be carried out upon agreement to evaluate fish-scale resistance.
- 7.4.2 – Adhesion test may be performed upon agreement; pretreatment and enameling conditions shall be stated in contract.
- 7.4.3 – Enamelability evaluation tests are recommended for first-time use or when enamel frit/process changes.
🔬 7.4.1 Anti-fishscale (Hydrogen permeation test)
Upon agreement, hydrogen permeation test (Annex B) may be carried out. Acceptance criteria by agreement.
📍 TH = tb/d² ; Electrolyte A: TH ≥ 6.7 min/mm². Electrolyte B: TH ≥ 6.7 min/mm² (negotiable for B/Ti steels).
🧪 7.4.2 Enamel adhesion test
Upon agreement, adhesion test may be performed. Pretreatment and enameling conditions shall be stated in contract.
🔄 7.4.3 Enamelability evaluation test
When using material first time or enamel frit/process changes, evaluation tests are recommended.
📋 Additional Technical Requirements
Surface quality (Table 8)
FB/FC/FD available. For FC/FD: stretcher strain free 6 months. No cracks, blisters, folds.
FB/FC/FD available. For FC/FD: stretcher strain free 6 months. No cracks, blisters, folds.
Oiling & rust (7.7)
Usually oiled, 6-month rust protection. Non-oiled: supplier not liable for rust/scratches.
Usually oiled, 6-month rust protection. Non-oiled: supplier not liable for rust/scratches.
📌 Surface texture: Dull Ra 0.6–1.9μm; Rough Ra >1.6μm (7.6). Dimensions per GB/T 708 (7.8). Enhanced dent resistance for anti-denting applications.
🏭 Manufacturing & Inspection
6.2 Decarburization annealing + skin-passed | 9.2 Batch ≤30t | 8.2 Tensile 1/batch | 10 Inspection doc type 3.1
📖 International grade comparison (Annex A)
GB/T 13790—2025: DC04ED ≈ EN 10209:2023 DC04ED, JIS G3133:2021 SPPE, ISO 5001:2012 VE03 Type 2.
GB/T 13790—2025: DC04ED ≈ EN 10209:2023 DC04ED, JIS G3133:2021 SPPE, ISO 5001:2012 VE03 Type 2.
🧪 Hydrogen Permeation Test Annex B
Thickness 0.50–3.00mm. TH = tb/d² ≥ 6.7 min/mm² (Electrolyte A). For B/Ti steels, results negotiable. DC04ED's extra-low carbon and decarburization annealing ensure consistent anti-fishscale performance for direct-on enameling.
✅ Why specifiers choose DC04ED enameling steel
- Extra-low carbon (≤0.004%) via decarburization annealing – enables direct-on (one-coat) enameling without ground coat
- Enhanced dent resistance – suitable for anti-denting applications
- Extra deep drawing performance – yield strength as low as 210 MPa, elongation up to 38%
- Fish scale resistance – validated by hydrogen permeation test (TH ≥6.7 min/mm²)
- Versatile enameling capability – suitable for both direct-on and traditional two-coat enameling
- 6-month mechanical property guarantee from manufacture date
- No stretcher strains for FC/FD surface quality within 6 months
- Hydrogen permeation / adhesion tests available upon agreement
- Oiled option: 6-month rust protection
Based on GB/T 13790—2025. Actual delivery subject to contract. Data verified per standard Tables 5, 6, 7 and Annex B. DC04ED features decarburization annealing for direct-on enameling with extra deep drawing capability and enhanced dent resistance.