GB/T 20878 17Cr18Ni9 Introduce
GB/T 20878 17Cr18Ni9 steel has excellent corrosion resistance in many different environments. It exhibits excellent resistance to corrosion in atmospheric conditions, dilute mineral acids, and most alkaline solutions. The alloy also has an excellent ability to resist galvanic corrosion when used in combination with other materials.
Smelting temperature:1664°C - 1134°C
Application:Stainless steel and heat resistant steel grades and chemical composition
GB/T 20878 17Cr18Ni9 Material Mechanical Properties
GB/T 20878 17Cr18Ni9 steel has superior mechanical properties compared to ordinary steel. It has an excellent strength-to-weight ratio and good levels of stiffness, ductility, and machinability. Its mechanical properties are largely dependent on the grade, with higher grades having higher strength and lower ductility.
The mechanical properties of the GB/T 20878 17Cr18Ni9 steel are as follows:
| YieldRp0.2 | ≤ 963 (MPa) |
| TeileRm | ≤ 538 (MPa) |
| ImpactKV/Ku | 14(J) |
| ElongationA | 41% |
| Reduction in cross section on fractureZ | 33% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 243 |
GB/T 20878 17Cr18Ni9 Material Thermal Properties
The thermal performance parameters of the GB/T 20878 17Cr18Ni9 steel are as follows:
| Temperature (°C) | 32 | 626 | 142 |
| Modulus of elasticity (GPa) | - | 852 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 22 |
| Thermal conductivity (W/m·°C) | - | 33.3 | 41.2 |
| Specific thermal capacity (J/kg·°C) | - | 411 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.44 | - | - |
| Deity (kg/dm³) | - | - | 332 |
| Poisson’s coefficient, ν | - | - | 113 |
GB/T 20878 17Cr18Ni9 Material Machining Technology
GB/T 20878 17Cr18Ni9 steel is an excellent material for machining and fabrication. Its high carbon content and strength make it an ideal choice for a range of applications. The selection of the proper cutting tools, cutting speeds, and feed rates are important for successful machining. HSS and HSC tools with a cutting speed of up to 350 m/min and a feed rate of 0.2 to 0.5 mm per revolution are generally recommended. Care should also be taken to ensure that the cutting tools are sharp in order to reduce cutting forces and increase cutting accuracy.