What will happen when heating Q345B steel plate?

The heating disadvantages of Q345B steel plate are:
1. Over-temperature: The heating temperature is high and the heating time is too long, so that the crystals grow up, the bonding between the crystals becomes weak, and the physical properties are affected.

2. Coarse crystals: Basically, if the heating temperature is too high again at over-temperature, the crystal boundary will be oxidized or melted by air, and cracks (damage) will occur during cold rolling.

3. De-C: The carbon content in the surface of the raw material is oxidized and reduced, which reduces the strength of the surface of the stainless steel sheet. Many carbon steels and high-alloy steels are not allowed to carburize.

4. Zinc ash; the air oxide film on the surface of the metal material, the higher the heating temperature, the longer the time, and the stronger the air oxidation atmosphere in the furnace, the more zinc ash will be formed, resulting in ablation of the metal material, resulting in defects in the surface of the Q345B steel sheet , (Black spots, tinplate, etc.).

5. Uneven heating: The temperature along the cross section of the billet or the length of each part is different, resulting in distortion, bending and internal cracking during cold rolling.