1. Chemical Composition
Table 1 – Reference Values for Chemical Composition (Ladle Analysis) of Electromagnetic Pure Iron
| Grade | Chemical Composition (Mass Fraction)/% | Chemical Composition (Mass Fraction)/% | Chemical Composition (Mass Fraction)/% | Chemical Composition (Mass Fraction)/% | Chemical Composition (Mass Fraction)/% | Chemical Composition (Mass Fraction)/% | Chemical Composition (Mass Fraction)/% | Chemical Composition (Mass Fraction)/% | Chemical Composition (Mass Fraction)/% | Chemical Composition (Mass Fraction)/% |
|---|---|---|---|---|---|---|---|---|---|---|
| Grade | C | Si | Mn | P | S | Al | Ti | Cr | Ni | Cu |
| DT4 | <0.010 | <0. 10 | <0.25 | <0.015 | <0.010 | 0.20 〜0.80 | <0.02 | <0. 10 | <0. 05 | <0. 05 |
| DT4A | <0.010 | <0. 10 | <0.25 | <0.015 | <0.010 | 0.20 〜0.80 | <0.02 | <0. 10 | <0. 05 | <0. 05 |
| DT4E | <0.010 | <0. 10 | <0.25 | <0.015 | <0.010 | 0.20 〜0.80 | <0.02 | <0. 10 | <0. 05 | <0. 05 |
| DT4C | <0.010 | <0. 10 | <0.25 | <0.015 | <0.010 | 0.20 〜0.80 | <0.02 | <0. 10 | <0. 05 | <0. 05 |
2. Mechanical Properties
Table 5 – Mechanical Properties and Surface Hardness
2.1 Upon the buyer's request, forged round bars, hot-rolled round bars, and hot-rolled plates may be tested for mechanical properties, and the results shall comply with the requirements specified in Table 5.
2.2 Cold-rolled thin sheets (strips) of electromagnetic pure iron delivered in the soft annealed condition shall undergo surface Vickers hardness testing. Three points shall be measured per specimen, and the average value shall be taken as the measurement result for that specimen. The hardness value shall be 85HV5~140HV5.
3. Electromagnetic Properties
Table 2 Electromagnetic Properties
| Grade | Coercivity Hc/(A/m) ≤ | Aging increase in coercivity ΔHc/(A/m) ≤ | Maximum permeability µm | Magnetic induction B/T | Magnetic induction B/T | Magnetic induction B/T | Magnetic induction B/T | Magnetic induction B/T | Magnetic induction B/T | Magnetic induction B/T | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grade | Coercivity Hc/(A/m) ≤ | Aging increase in coercivity ΔHc/(A/m) ≤ | Maximum permeability µm | Standard grade | DT4 | 96.0 | 9.6 | 0.0075 | ≥1.20 | ≥1.30 | ≥1.40 | ≥1.50 | ≥1.62 | ≥1.71 | ≥1.80 |
| DT4 | 96.0 | 9.6 | 0.0075 | ≥1.20 | ≥1.30 | ≥1.40 | ≥1.50 | ≥1.62 | ≥1.71 | ≥1.80 | |||||
| DT4A | 72.0 | 7.2 | 0.0088 | ≥1.20 | ≥1.30 | ≥1.40 | ≥1.50 | ≥1.62 | ≥1.71 | ≥1.80 | |||||
| DT4E | 48.0 | 4.8 | 0.0113 | ≥1.20 | ≥1.30 | ≥1.40 | ≥1.50 | ≥1.62 | ≥1.71 | ≥1.80 | |||||
| DT4C | 32.0 | 4.0 | 0.0151 | ≥1.20 | ≥1.30 | ≥1.40 | ≥1.50 | ≥1.62 | ≥1.71 | ≥1.80 |
Note: B200, B300, B500 ... B10000 denote the magnetic induction at magnetic field strengths of 200 A/m, 300 A/m, 500 A/m ... 10,000 A/m, respectively.
4. Surface quality
Table 3 Provisions of the applicable standards for the surface quality of electromagnetic pure iron products.
The surface quality of electromagnetic pure iron products shall comply with the provisions of the applicable standards listed in Table 3.
| Product type | Applicable Standard | Product type | Applicable Standard |
|---|---|---|---|
| Continuous Cast Square and Rectangular Billets of Electromagnetic Pure Iron | YB/T 2011 | Forged Round Bars of Electromagnetic Pure Iron | GB/T 699 |
| Continuous Cast Slabs of Electromagnetic Pure Iron | YB/T 2012 | Hot-Rolled Sheets (Strips) of Electromagnetic Pure Iron | GB/T 711 |
| Primary Mill Blooms of Electromagnetic Pure Iron | YB/T 004 | Cold-Drawn Round Bars of Electromagnetic Pure Iron | GB/T 3078 |
| Hot-Rolled Round Bars of Electromagnetic Pure Iron | GB/T 699 | Cold-Rolled Thin Sheets (Strips) of Electromagnetic Pure Iron | GB/T 13237 |
| Hot-Rolled Wire Rod of Electromagnetic Pure Iron | GB/T 701 |