What is the specific concept of thread steel through water and what is the difference?
Water cooling technology is used in the production of rebar, and the temperature of controlled cooling termination is higher than the recrystallization temperature of the material. If the temperature is obviously lower than the recrystallization temperature, the surface of the reinforcing steel is easy to form a thin layer of quenching and tempering structure. Quenching and tempering organization once formed, will undermine the strong cuby rebar and welding performance.
The principle of water cooling technology to produce rebar is that austenite can be strongly deformed in the process of continuous rolling in the recrystallization zone, resulting in very fine, strongly hardened austenite grains with a lot of defects. With the high speed of cooling on the enhanced cooling of austenite, in a very short period of time, generally not more than 0.5s, is rapidly cooled to near the phase transition temperature, inhibit the growth of austenite grain, try to keep the hardening state of austenite. When the temperature is near the phase transition point, the fine hardening austenite grains are transformed into ferrite with proper grain size under proper air cooling conditions.
Most of the thread steel is subjected to self - tempering after water cooling, and the tempered bainite is obtained. The advantage is that the strength will be better; the disadvantage is that after rolling through water, the surface oxide film of steel is destroyed, rust is sure
