Solution treatment and annealing are two different heat treatment methods, which have significant differences in purpose, process, effect, and application.

Solid solution treatment

Definition: Solid solution treatment refers to the heat treatment process of heating an alloy to a high temperature single-phase zone and maintaining a constant temperature, so that the excess phase is fully dissolved into the solid solution, and then rapidly cooled to obtain a supersaturated solid solution. Because the operation process is similar to quenching, it is also known as "solid solution quenching".

Purpose:

Dissolve carbides and γ 'in the matrix to obtain a uniform supersaturated solid solution, which facilitates the precipitation of fine and evenly distributed carbides and strengthening phases such as γ' during aging.

Eliminate the stress generated by cold and hot processing, causing the alloy to undergo recrystallization.

Obtain appropriate grain size to ensure the high-temperature creep resistance of the alloy.

Process:

Heat the alloy to a suitable temperature above the solubility curve and below the solidus line for a certain period of time to dissolve the second phase into the solid solution.

Quickly cool in water or other media to suppress the re precipitation of the second phase and obtain a supersaturated solid solution at room temperature.

effect:

Improve the strength and plasticity of castings.

Improve the corrosion resistance of alloys.

Application: Suitable for various special steels, high-temperature alloys, special performance alloys, and non-ferrous metals, especially alloys that require improved mechanical properties and corrosion resistance.

annealing

Definition: Annealing is a heat treatment process in which a metal or alloy is heated to an appropriate temperature, held for a certain period of time, and then slowly cooled.

Purpose:

Eliminate internal stress in cast, forged, and welded parts, stabilize dimensions, and reduce deformation and crack tendency.

Reduce hardness and improve machinability.

Refine grain size, adjust structure, and eliminate structural defects.

Process:

Heat the metal or alloy to the desired temperature (usually below the solidus temperature).

Maintain sufficient insulation time to induce organizational transformation.

Slowly cool to room temperature, usually with furnace cooling.

effect:

Eliminate internal stress and stabilize casting dimensions.

Reduce hardness and improve cutting performance.

Refine grain size, improve microstructure, and enhance toughness.

Application: Widely used in the pretreatment, intermediate treatment, and final treatment of metal materials to improve their processing and usability properties.

summary

There are significant differences between solution treatment and annealing in terms of purpose, process, effect, and application. Solid solution treatment mainly focuses on obtaining supersaturated solid solutions through high-temperature dissolution and rapid cooling to improve the strength and corrosion resistance of materials; Annealing, on the other hand, mainly focuses on eliminating internal stress, reducing hardness, refining grains, and improving microstructure to enhance the processing and usability of materials. The two heat treatment methods each have their unique roles and application areas in metal material processing.