Scarring of carbon steel flanges
The scab of carbon steel flange is a peelable film on the local area of carbon steel flange on the rolled surface.
The formation of scabs on carbon steel flanges is due to the splashing of molten steel during casting and condensation on the surface of ingots. During rolling, the film of carbon steel flanges is pressed and attached to the surface of rolled products, which is called scabs. After acid cleaning, the film of forged carbon steel flange forgings will peel off and become surface defects of forgings.
Lamellar fracture of carbon steel flange
The characteristic of lamellar fracture of carbon steel flange is that its fracture or section is very similar to the broken slate and bark.
The lamellar fracture of carbon steel flange mostly occurs in alloy steel (chromium nickel steel, chromium nickel tungsten steel, etc.), and it is also found in carbon steel. The defects of this carbon steel flange are caused by the non-metallic inclusions, dendrite segregation, porosity and other defects in the steel, which are elongated along the rolling direction in the process of forging and rolling, making the steel appear lamellar. If there are too many impurities, there is a danger of delamination and fracture in the forging. The more serious the lamellar fracture is, the worse the plasticity and toughness of the steel are. Especially, the transverse mechanical properties of carbon steel flanges are very low, so the steel with obvious lamellar defects is unqualified.
Bright line (bright area) of carbon steel flange
The bright line of carbon steel flange is a fine reflective line with crystal brightness on the longitudinal fracture. Most of it runs through the whole fracture of carbon steel flange, and most of it is produced in the axial part.
