China · GB
NM50
GB/T 33966:2017 — Seamless abrasion-resistant steel pipes for mortar service
Chemical composition
| Element | min | max | Similar | Remarks |
|---|---|---|---|---|
| C | 0.42 | 0.49 | ||
| Cu | 0.2 | |||
| Mn | 1.4 | 1.8 | ||
| P | 0.025 | |||
| S | 0.025 | |||
| Si | 0.17 | 0.37 |
Mechanical properties
| Heat treatment / condition | Yield strength | Tensile strength | Elongation | Reduction of area | Impact energy | Hardness |
|---|---|---|---|---|---|---|
| steel tubes, hot rolled | ≥420 | ≥750 | ≥14 | HR ≥50 |
Heat treatment
| Type | 3 | 4 |
|---|---|---|
| Heat-treatment process | 淬火+回火 | 840℃±30℃淬火，冷却剂水；180℃±50℃回火。 |