Heat Treatment Process:
1.Solution Treatment: Solution treatment is usually applied first. Solution treatment is to heat the alloy to a solution temperature (generally between 1100-1200 °C) to make the alloying elements in the alloy evenly dissolved in the matrix, and then quickly cooled to maintain its uniform solution structure.
2.*Aging treatment**: After solution treatment, aging treatment is usually required. Aging treatment is to keep the solution alloy at a lower temperature for a certain period of time (generally between 800-1000 °C), so that the alloying elements can be re-precipitated to form a diffusely distributed strengthening phase, so as to improve the strength and hardness of the alloy.
3.*Resolution treatment**: Sometimes there may still be some residual stress or incomplete precipitation of alloying elements after aging treatment, at this time, resolution treatment can be carried out, and the stability and performance of the alloy can be improved by heating the solution again and cooling it quickly.
4.*Rapid cooling treatment**: In special cases, it may also be necessary to carry out rapid cooling treatment, that is, rapid cooling at high temperatures to obtain a finer microstructure and high strength and hardness.
5.*Quenching Treatment**: For situations where hardness and strength need to be further improved, GH15 alloy can also be quenched. Quenching is the rapid cooling of the solution treated alloy to room temperature to obtain a martensitic structure, thereby improving the hardness and strength of the alloy.
Mechanical properties: 1Tensile Strength: Typically at 750 degrees Celsius, the tensile strength of GH15 alloy can reach more than 1200 MPa.
2.Yield Strength: At high temperatures, the yield strength of GH15 alloy is generally above 800 MPa.
3.Elongation: It usually has good elongation properties, and its elongation can be maintained at more than 20% at high temperatures.
4.Hardness: After a suitable heat treatment, a high hardness can be obtained, usually above HRC 30.
Processability: 1Malleability: It has good malleability, and the shape and size of the alloy can be changed by hot working methods, such as forging and rolling. The hot working temperature is usually between 950-1200 degrees Celsius.
2.Machinability: Cutting can be performed prior to hot working. However, due to its high hardness and corrosion resistance, it can cause cutting tools to wear out quickly. Therefore, when performing cutting operations, it is necessary to use the right cutting process and tool material to ensure machining quality and tool life.
3.Weldability: It has good welding performance and can be connected by common welding methods such as arc welding, TIG welding, resistance welding, etc. It should be noted that in the welding process, appropriate welding materials and process parameters should be selected according to the specific alloy composition and heat treatment status to ensure the quality and performance of the welded joint.
It also contains small amounts of copper, molybdenum, titanium, aluminum, zirconium, carbon, and other elements. The following is a common range of chemical compositions (in weight %) of GH15 alloys
Nickel (Ni): 440-50.0%
Chromium (CR): 140-18.0%
Molybdenum (Mo): 15-3.0%
Copper (Cu): 05-1.5%
Titanium (Ti): 10-2.5%
Aluminum (AL): 05-1.5%
Zirconium (zr): 001-0.5%
Carbon (c): 005-0.15%
Silicon (Si): 05%
Manganese (mn): 10%
Phosphorus (p): 003%
Sulfur (s): 0015%
It is important to note that the specific chemical composition and composition range of GH15 alloy may vary depending on the manufacturer and product standard. In specific applications, it is necessary to select suitable processing and use conditions according to the chemical composition and characteristics of GH15 alloy to ensure its reasonable performance and application effect.