France · AFNOR NF
20 NC 6
NF A35-551 — Unalloyed and alloy heat treated steels. Grades and types. Common requirements(A1-1975)
Chemical composition
| Element | min | max | Similar | Remarks |
|---|---|---|---|---|
| C | 0.16 | 0.21 | ||
| Cr | 0.9 | 1.2 | ||
| Mn | 0.6 | 0.9 | ||
| Ni | 1.2 | 1.5 | ||
| P | 0.035 | |||
| S | 0.035 | |||
| Si | 0.1 | 0.4 |
Mechanical properties
| Heat treatment / condition | Yield strength | Tensile strength | Elongation | Reduction of area | Impact energy | Hardness |
|---|---|---|---|---|---|---|
| bars, wire, Heat treated, <= 16 mm, steel bars | 850 | 1200 1550.00 | 8 | 50 | ||
| bars, wire, Heat treated, <= 16 mm, HB | 钢棒 163 217.00 | |||||
| bars, HB, wire | 钢棒 207.00 |
Heat treatment
| Type | 1 |
|---|---|
| Heat-treatment curve | TTT |
| Heat-treatment curve | Hardness-Tempering |
| Heat-treatment curve | CCT |
| Heat-treatment curve | 淬透性 |