Possible defects of P235GH steel plate

It is inevitable that there will be different problems in the production process of the steel plate. What defects may appear on P235GH steel plate?

(1) Cracks. It mainly refer to the cracks caused by heat treatment or white spots. Among them, heat treatment cracks are perpendicular to the rolling surface of P235GH steel plate caused by thermal stress in the heat-affected zone during cutting or irregular heat treatment. Internal cracks appear occasionally, and most of time on the surface of P235GH steel plate. The white spot is the small cracks whose harm is relatively small, and it formed when the hydrogen doesn't have time to diffuse during the rolling and cooling process.

(2) Layered. Layering is mainly formed due to incomplete flattening and welding of sulfides, metal oxides, and non-metallic inclusion plates in rolling engineering; most of the defects are basically parallel to the slab surface , appearing in the middle or the center of P235GH steel plate.

(3)Inclusion. The distribution of inclusion defect parts is often irregular, which is caused by the failure of welding due to the small compression ratio during rolling, and the inclusion of P235GH steel plate can be divided into two categories: external inclusions and internal inclusions. Foreign non-metallic inclusions are mostly formed due to the refractory material falling off on the furnace wall; internal inclusions are formed by the inclusion of low melting point inclusions mixed in P235GH molten steel. More central carbon and manganese segregation formed.