Round steel is classified as hot rolled, forged and cold drawn. The specifications of hot rolled Round bars are 5.5-250 mm. Among them: 5.5-25 mm of small Round bars mostly supplied in bundles of straight bars, commonly used as reinforcement, bolts and various mechanical parts; greater than 25 mm of Round bars, mainly used in the manufacture of mechanical parts, seamless steel pipe billets, etc..
In thermal processing, there are two common heating methods, one is local heating using acetylene flame, this method is simple, but the heating area is small. The other is heating in an industrial furnace, which is not as easy as the previous method, but has a large heating area. Considering the specific processing conditions and components, we use the acetylene flame heating method for heating.
When the parts are formed using hot work, the heating temperature should be controlled at 900 ~ 1000 ℃; carbon structural steel and low-alloy structural steel in the temperature down to 700 ℃ and 800 ℃ respectively before the end of processing. Heating temperature is too high, heating time is too long, will cause changes in the internal organization of the steel, damage the mechanical properties of the raw material material.
The heating temperature of steel can be judged by the colour it appears when heated
After the steel has reached the specified temperature, the steel is formed and processed.
Bending the radius of the corner should not be too large, nor too small; too large due to the impact of rebound, so that the accuracy of the component is not easily guaranteed, too small is easy to produce cracks.
After forming the components, they are to be cooled naturally and protected.