GB/T 20878 16Cr25Ni20Si2 Introduce
GB/T 20878 16Cr25Ni20Si2 stainless steel is a one-piece austenitic chromium-nickel alloy, usually used in applications that require high strength, corrosion and abrasion resistance. It contains chromium, nickel and molybdenum, as well as phosphorus and sulfur, which improve its mechanical properties and resistance to oxidation and corrosion. The addition of molybdenum stabilizes the austenitic structure and increases the alloy's resistance to pitting, crevice corrosion and general corrosion.
Smelting temperature:1621°C - 1462°C
Application:Stainless steel and heat resistant steel grades and chemical composition
GB/T 20878 16Cr25Ni20Si2 Material Chemical Composition
The chemical composition of the GB/T 20878 16Cr25Ni20Si2 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Chromium (Cr) | 24.0000 | 27.0000 |
| Nickel (Ni) | 18.0000 | 21.0000 |
| Sulfur (S) | - | 0.0300 |
| PhOsphorus (P) | - | 0.0450 |
| Manganese (Mn) | - | 1.5000 |
| Silicon (Si) | 1.5000 | 2.5000 |
| Carbon (C) | - | 0.2000 |
| PhOsphorus (P) | - | 0.0400 |
GB/T 20878 16Cr25Ni20Si2 Material Mechanical Properties
The mechanical properties of GB/T 20878 16Cr25Ni20Si2 steel depend largely on its chemical composition. Generally, the higher the carbon content and low alloy levels means higher toughness and strength.GB/T 20878 16Cr25Ni20Si2 grades ranging from 0.3 to 2.5 percent carbon are considered to have excellent mechanical properties. Higher levels of carbon increase strength, but also reduce ductility and toughness.
The mechanical properties of the GB/T 20878 16Cr25Ni20Si2 steel are as follows:
| YieldRp0.2 | ≤ 432 (MPa) |
| TeileRm | ≤ 999 (MPa) |
| ImpactKV/Ku | 33(J) |
| ElongationA | 13% |
| Reduction in cross section on fractureZ | 33% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 323 |
GB/T 20878 16Cr25Ni20Si2 Material Thermal Properties
The thermal performance parameters of the GB/T 20878 16Cr25Ni20Si2 steel are as follows:
| Temperature (°C) | 32 | 725 | 658 |
| Modulus of elasticity (GPa) | - | 615 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 34 |
| Thermal conductivity (W/m·°C) | - | 42.3 | 13.2 |
| Specific thermal capacity (J/kg·°C) | - | 431 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.41 | - | - |
| Deity (kg/dm³) | - | - | 442 |
| Poisson’s coefficient, ν | - | - | 243 |
GB/T 20878 16Cr25Ni20Si2 Material Machining Technology
The type of cutting tool chosen depends on the end-use application and the desired cutting performance. In general, high-speed steel (HSS) or high-speed cobalt (HSC) tools are best for machining GB/T 20878 16Cr25Ni20Si2 steel as they have excellent cutting properties and can cope with high cutting speeds and feeds. Carbide grade tools may be used for high-shear or high-feed applications.