1. Chemical Composition
Table 1 – Chemical composition, unit: %
For all steel grades in this table, Cu shall not exceed 0.30%, Ni 0.20%, and Cr 0.20%. Note a) The lower limit for Si may be set to less than 0.10% by agreement between supplier and purchaser. b) The B content may be 0.0005% or higher by agreement between supplier and purchaser.
2. Hardenability
Table 3 Distance from quenched end and hardness
3. Mechanical properties of wire rod
Table 5 Mechanical properties of wire rod resulting from the DA process
Notes: 1. For wire diameters exceeding 20 mm, the tolerance is the value in Table 2 minus 5. No tolerance is specified for diameters of 3 mm or less. 2. 1 N/mm² = 1 MPa
4. Decarburized layer depth
Table 6 Permissible limits for average decarburized layer depth
| Average decarburized layer depth | ||
|---|---|---|
| Wire diameter (mm) | Ferrite decarburized layer depth | Total decarburized layer depth |
| ≤15 | ＜0.02 | ＜0.15 |
| 15＜d≤25 | ＜0.03 | ＜0.20 |
| 25＜d≤32 | ＜0.04 | ＜0.25 |
For SWCH30K to SWCH50K wire, when specified by the purchaser, the test in 10.3.1 shall be performed. The permissible limit for the average decarburized layer depth shall be in accordance with Table 4. However, for wire with a diameter exceeding 32 mm, the limits shall be agreed upon between the supplier and the purchaser.
5. Wire diameter tolerance and out-of-roundness
Table 7 Tolerances and out-of-roundness for wire diameter
| Table 7 Wire diameter tolerances and deviations | ||
|---|---|---|
| Unit: mm | ||
| Wire diameter | Permissible deviation | Out-of-roundness |
| ≤3 | 0-0.025 | 0.013 |
| 3<d≤6 | 0-0.030 | 0.013 |
| 6<d≤10 | 0-0.036 | 0.013 |
| 10<d≤18 | 0-0.043 | 0.013 |
| 18<d≤30 | 0-0.070 | 0.013 |
| 30<d≤40 | 0-0.100 | 0.013 |
| 40<d≤50 | 0-0.150 | 0.013 |
Note (3) Out-of-roundness refers to the difference between the maximum and minimum diameters within the same cross-section of the wire.