The solution treatment temperature of 304 stainless steel plate should be around 1080 ~ 1100 ℃, and the cooling method is water cooling or air cooling. In the cold working process, annealing is required, and the temperature is generally around 890 degrees Celsius. After a period of time, the final heat preservation stage will enter the water cooling stage.
The quenched stainless steel plate was put back into the heat treatment furnace, heated to 500° C., kept for 2 hours, taken out, and cooled to room temperature in the air. The hardness of stainless steel plate should generally be hb200~230. If the hardness of the stainless steel plate is to be reduced to the hardness before quenching, the furnace temperature can be increased to 850 ℃, and then the hardness of the steel will decrease as the furnace cools.
304 stainless steel plate quenching is a heat treatment method that heats the steel above the critical temperature, keeps it for a period of time, and then quickly puts it into the quenching medium, suddenly reduces its temperature, and rapidly cools it at a speed higher than the critical cooling rate, so as to obtain a A non-equilibrium structure dominated by martensite. Quenching increases the strength and hardness of the steel, but reduces its ductility. Quenching media commonly used in quenching include water, oil, alkaline water and salt solutions.
The 304 stainless steel plate is heated to 40~60oC above the critical temperature for a period of time, and then cooled in air is called normalizing. The 304 stainless steel plate is heated to the quenching temperature, kept for a period of time, and then rapidly cooled in water, brine or oil (single material in air), which is called quenching heat treatment.
In summary, the above is the main content of how 304 stainless steel plate is quenched and softened. We recommend that 304 stainless steel not be quenched or it will lose its hardness. 304 stainless steel is austenitic stainless steel, which cannot be quenched and can only be improved by solid solution. Austenitic stainless steel refers to stainless steel with an austenitic structure at room temperature. When the Cr content is about 18%, Ni8% to 10%, and the C content is about 0.1%, the steel has a stable austenite structure. Austenitic chromium-nickel stainless steels include the well-known 18Cr-8Ni steel and high Cr-Ni series steels developed by increasing the content of Cr and Ni and adding elements such as Mo, Cu, Si, Nb, and Ti. Austenitic stainless steels are non-magnetic and have high toughness and plasticity, but their strength is low. Phase transition does not strengthen it. It can only be strengthened by cold working. Adding s, CA, Se, TE and other elements, has good free cutting performance.