Annealing method of annealing furnace

The annealing furnace can be integrated into other furnace treatment steps, such as oxidation, or it can be treated separately. The annealing furnace is completed by equipment specially designed to heat semiconductor wafers. The annealing furnace is an energy-saving circulating furnace with super energy-saving structure and fiber structure, which can save electricity by 60%.

In modern society, annealing furnaces are used very much. What is the specific annealing method?

Low temperature annealing

A heat treatment process that heats steel to a temperature slightly lower than Ac1. The heat treatment process of maintaining a certain period of time and then slowly cooling is called low temperature annealing. Because low-temperature annealing does not have a recrystallization process, it cannot refine the grain and structure of the steel, but it can eliminate or reduce the internal stress in the steel, reduce the hardness and improve the cutting performance. Low-temperature annealing has a short heating time, low cost, and small loss of oxidative decarburization on the steel surface, so it can replace complete annealing or incomplete annealing in some cases.

Low temperature annealing of ingot steel

Low-temperature annealing can reduce the hardness of the steel ingot, eliminate or reduce the stress in the as-cast state, and is especially suitable for steel with high hardenability and not easy to soften by ordinary annealing. Bainite or martensite transformation will inevitably occur on the surface of the steel ingot, which not only eliminates stress, but also makes surface cleaning difficult. Low temperature annealing is effective. The low-temperature annealing heating temperature of the ingot steel ingot is Ac1, which is lower than 20 --- 30°C. In theory, the closer the temperature is to Ac1, the better the effect. However, in actual production, due to temperature fluctuations, the temperature is slightly higher than Ac1 and a part of austenite is produced, which makes the surface hardness of the steel ingot higher.

Therefore, 680-710C is generally used for various structural steels, spring steels and hot die cast steel ingots, while 640-680C is generally used for high alloy steels. The heating rate of the steel ingot during low temperature annealing is 100-200C/h; the holding time is r = 8.5 Q/4, where Q is the furnace load (t).