How to distinguish the quality of high toughness Q235B steel plate?

Distinguish whether the high toughness Q235B steel plate is good or bad from the following aspects:

1. The fake and inferior Q235B steel plate is prone to expansion and contraction, which is a variety of curves produced by the surface layer of Q235B steel plate. This kind of defect is usually around the vertical direction of all commodities.

2. The surface of fake and inferior Q235B steel plate often has surface condition. The surface of Q235B steel plate is irregular and uneven due to serious damage of rolling groove.

3. The surface layer of fake and inferior Q235B steel plate is easy to cause scab. The main reason is that the material of fake and inferior Q235B steel plate is uneven and there are many residues. Secondly, the guide and guard equipment of the manufacturer of fake and inferior material is simple and easy to stick to the steel. This residue is easy to cause scab after hot rolling the strip steel.

4. The surface layer of fake and inferior high toughness Q235B steel plate is easy to cause cracks. The reason is that the raw material is clay brick, which has many air holes. During the whole process of refrigeration, due to the effect of welding stress, the brick will have cracks after cold rolling.

5. The fake and inferior Q235B steel plate has no metal texture and is dark red or similar to pig iron color. The reason lies in that its embryo material is earth brick, and the cold rolling temperature of fake and inferior products is not standardized. Their steel temperature is estimated according to the estimation, so it is impossible to carry out cold rolling in accordance with the specified martensite area, so the characteristics of Q235B steel plate are not qualified.

6. The inner diameter of the fake and inferior Q235B steel plate fluctuates greatly because of the unstable temperature of the steel and the internal and external surfaces.