JIS G3445 STKM19A Introduce
JIS G3445 is a standard carbon steel grade that is used in machinery and applications. It covers the dimensions, chemical composition, mechanical properties and requirements of the steel. The dimensions include the outer dimensions, wall thickness, inner dimensions, length and mass. The chemical composition includes the desired amount of carbon and the allowable levels of impurities such as sulfur and phosphorus. The mechanical properties include the strength, elongation, hardness and impact resistance of the steel.
Smelting temperature:1396°C - 1965°C
Application:Carbon steel pipe for mechanical structure
JIS G3445 STKM19A Material Chemical Composition
The chemical composition of the JIS G3445 STKM19A steel are as follows:
| Element | Min | Max |
|---|---|---|
| Silicon (Si) | - | 0.5500 |
| Sulfur (S) | - | 0.0400 |
| PhOsphorus (P) | - | 0.0400 |
| Manganese (Mn) | - | 1.5000 |
| Carbon (C) | - | 0.2500 |
JIS G3445 STKM19A Material Mechanical Properties
The carbon content of the alloy makes it especially good for the production of heavy-duty and high-strength parts. JIS G3445 STKM19A steel exhibits a high level of ductility without any loss of strength. This, in combination with its good weldability, makes it ideal for applications that require forming and welding, as well as for machine shafts, gears, and axles.
The mechanical properties of the JIS G3445 STKM19A steel are as follows:
| YieldRp0.2 | ≤ 174 (MPa) |
| TeileRm | ≤ 247 (MPa) |
| ImpactKV/Ku | 42(J) |
| ElongationA | 43% |
| Reduction in cross section on fractureZ | 14% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 311 |
JIS G3445 STKM19A Material Thermal Properties
The thermal performance parameters of the JIS G3445 STKM19A steel are as follows:
| Temperature (°C) | 21 | 728 | 174 |
| Modulus of elasticity (GPa) | - | 397 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 44 |
| Thermal conductivity (W/m·°C) | - | 41.3 | 44.2 |
| Specific thermal capacity (J/kg·°C) | - | 312 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.22 | - | - |
| Deity (kg/dm³) | - | - | 142 |
| Poisson’s coefficient, ν | - | - | 241 |
JIS G3445 STKM19A Material Machining Technology
JIS G3445 STKM19A steel can be heat-treated at high temperatures to increase its strength and other mechanical properties. The alloy is very tolerant of heat up to 800°C. It is normally annealed at around 650°C and cooled slowly in order to recover its strength. On the other hand, when subjected to extreme temperatures, it is known to form martensite, an extremely hard form of steel that has a unique molecular structure. It is ideal for use in applications that require tremendous strength and wear resistance, such as high-pressure industrial applications.