What is DC05EK Enameling Steel?
If you need ultra deep drawing performance with superior vitreous enameling characteristics, DC05EK is the premium grade you should consider.
DC05EK is a cold-rolled low carbon steel specifically optimized for traditional enamel coating (EK suffix) with stamping level 05 (ultra deep drawing). With ultra-low carbon (≤0.02%), the lowest phosphorus content (≤0.020%) among EK series, and excellent plastic strain ratio (r90 ≥1.7), it delivers outstanding formability for the most demanding deep-drawn parts while ensuring superior enamel adhesion and anti-fishscale performance.
When you use DC05EK, you benefit from exceptional formability for highly complex geometries, consistent surface quality after firing, and minimal rejects due to fish scaling, blistering, or poor adhesion.
Typical applications include complex deep-drawn enamelware, water heater liners, sanitary ware, bathtubs, automotive enamel components, and high-end home appliance parts. If you need both extreme drawability and a flawless enamel finish, DC05EK gives you the highest performance foundation.
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 DC05EK (Traditional Enameling Process / Ultra Deep Drawing Quality)
📌 Designation System Clause 4.2
DC05EK consists of four parts:
- D — Steel flat product for cold forming
- C — Cold rolled condition
- 05 — Stamping level: Ultra deep drawing (Level 05)
- EK — Enamelling type: Suitable for traditional enameling process
📖 Note: "ED" suffix indicates direct-on enameling process (also suitable for traditional), while DC05EK uses "EK" for traditional enameling with premium ultra deep drawability and r90 ≥1.7.
📊 DC05EK vs Other Enameling Grades – Why Choose DC05EK?
1️⃣ vs DC01EK
DC01EK: General purpose (C ≤0.07%)
DC05EK: Ultra deep drawing – C ≤0.02%, ultra-low P ≤0.020%
Elongation: 36% vs 30% (t>0.70mm)
r90 ≥1.7 vs not required
2️⃣ vs DC03EK
DC03EK: Drawing quality (C ≤0.07%)
DC05EK: Ultra deep drawing – significantly lower carbon
Yield strength: ≤220 MPa vs ≤240 MPa (t>0.70mm)
Superior r90 value for deep drawing
3️⃣ vs DC04EK
DC04EK: Extra deep drawing (C ≤0.06%)
DC05EK: Ultra deep drawing – C ≤0.02%, P ≤0.020%
Better enamel adhesion due to lower P
Higher r90 value for complex shapes
4️⃣ Key Advantages
- Ultra-low carbon (≤0.02%) for maximum formability
- Lowest phosphorus (≤0.020%) for superior enamel adhesion
- Highest elongation (≥36% for t>0.70mm)
- Plastic strain ratio r90 ≥1.7 (0.50-2.00mm) / ≥1.5 (2.00-3.50mm)
- 6-month stretcher strain free (FC/FD)
- Hydrogen permeation validated (TH ≥6.7)
💡 Key takeaway: DC05EK delivers the highest formability among EK-series enameling steels with ultra-low carbon (≤0.02%) and the strictest phosphorus control (≤0.020%). Choose DC05EK when your part requires the most complex ultra deep drawing geometries while maintaining superior enamel adhesion and fish-scale resistance. The r90 ≥1.7 ensures excellent deep drawability.
🏺 Enameling Performance
🎯 Designed for
- Traditional two-coat enameling
- Complex ultra deep-drawn components
- Reduced fish-scale & blistering
✨ Key Characteristics
- Excellent enamel adhesion (lowest P ≤0.020%)
- Proven fish-scale resistance (TH ≥6.7)
- Superior ultra deep drawing capability
- Ultra-low carbon (≤0.02%) for surface quality
- High plastic strain ratio r90 ≥1.7
⚙️ What makes DC05EK the premium enameling steel? Its ultra-low carbon chemistry (≤0.02%) and lowest phosphorus content (≤0.020%) deliver exceptional formability and the cleanest surface for enamel coating. The hydrogen permeation test validates fish scale resistance (TH ≥6.7 min/mm²), while the highest elongation (up to 36%) and r90 ≥1.7 enable the most complex ultra deep-drawn shapes without cracking.
⚙️ Chemical Composition Clause 7.1 – Table 5 (Ladle analysis)
| Grade | C (%) | Mn (%) | P (%) | S (%) | Als (%) | Ti (%) |
|---|---|---|---|---|---|---|
| DC05EK | ≤0.02 | ≤0.50 | ≤0.020 | ≤0.050 | ≥0.010 | — |
🔬 Permissible deviations for product analysis according to GB/T 222 (Clause 7.1.2). Ultra-low carbon (≤0.02%) and lowest phosphorus (≤0.020%) among EK series provide maximum formability and superior enamel adhesion.
📊 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 |
r90 0.50~2.00mm |
r90 >2.00mm |
|---|---|---|---|---|---|---|---|---|---|
| DC05EK | ≤260 | ≤240 | ≤220 | 270~350 | ≥32 | ≥34 | ≥36 | ≥1.7 | ≥1.5 |
📐 When yield phenomenon not obvious, use Rp0.2. 🔧 Lower yield strength limit of 140 MPa negotiable. 🧪 P6 transverse specimen. Plastic strain ratio r90 measured at 15% plastic strain (Table 9 note). For thickness ≥1.5mm, yield strength upper limit is 225 MPa.
📏 Stretcher Strain Clause 7.3 – Table 7
| Grade | Stretcher strain requirements |
|---|---|
| DC05EK (and DC01EK, DC03EK, DC04EK, DC03ED, DC04ED) | ✔️ 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). Plastic strain ratio r90 ≥1.7 for thickness 0.50-2.00mm, ≥1.5 for thickness >2.00mm (Table 6).
🏭 Manufacturing & Inspection
6.2 Annealed + 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: DC05EK ≈ EN 10209:2023 DC05EK, ISO 5001:2012 VE04 Type 1.
GB/T 13790—2025: DC05EK ≈ EN 10209:2023 DC05EK, ISO 5001:2012 VE04 Type 1.
🧪 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. DC05EK's ultra-low carbon and aluminum-killed chemistry ensure consistent anti-fishscale performance.
✅ Why specifiers choose DC05EK enameling steel
- Ultra-low carbon (≤0.02%) & lowest phosphorus (≤0.020%) – cleanest surface, maximum formability, fewest enamel defects
- Premium ultra deep drawing performance – yield strength as low as 220 MPa, elongation up to 36%
- High plastic strain ratio – r90 ≥1.7 (0.50-2.00mm) / ≥1.5 (>2.00mm) for superior deep drawability
- Fish scale resistance – validated by hydrogen permeation test (TH ≥6.7 min/mm²)
- 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. r90 values per Table 6 footnote.