40 steel -structural high-quality carbon steel, designed for construction and engineering. It conforms to the GOST 1050-88 and DSTU 7809 standard.
Classification: High-grade structural carbon steel.
Product: Steel plates in sheets and coils, rolled products, including shaped.
Chemical composition of 40 steel, according to DSTU 7809, %
| | Si | Mn | Ni | P | S | Cr | Cu |
| | 0.17-0.37 | 0.50-0.80 | ≤0.30 | ≤0.035 | ≤0.040 | ≤0.25 | ≤0.30 |
Mechanical properties of 40 steel after normalization
| Creep limit, not less | Short-term tensile strength ReH, not less | Minimum elongation ratio, %, not less | Contraction ratio, %, not less |
| 335 | 570 | 19 | 45 |
Analogues to 40 steel
| US | 1040, 1042, G10400, G10420 |
| Japan | S40C, S43C, SWRCH38K, SWRCH40K |
| EU | 1.1186, C35, C40, C40E |
| China | 40, ML40 |
| Sweden | 1555, 1650 |
| Poland | 40, 40A, 40rs, D40, P40 |
| Romania | OLC40, OLC40X |
| Czech Republic | 12041 |
| Australia | 1040, M1040 |
| South Korea | SM40C |
Application
40 steel is widely used in piston rods, gear wheels, crankshafts, ring gears, flywheels, axles and bolts. It also features in medium-sized components like long axles, feed rods, cogs, etc, that are used in components for pipe fittings following preliminary quenching, which is conducted during the assembly of agricultural vehicles. 40 steel is used in fastenings for pipelines/boilers for thermal and nuclear power plants, and block/connecting components for turbines.
Welding
40 steel has limited welding capacity (to achieve a high-quality weld, the steel must be pre-heated before and annealed after the welding). The welding methods for this steel are manual-arc, automatic-arc and electroslag welding. Limitless contact welding can be applied.
