A method for making visible from the top by a helicoidal guide for a subsequent error control errors to moulded articles from steel

摘要

The surface defects in steel blanks such as billets or slabs etc. are made visible by descaling the surface, specifically carrying this out at a temp. below that at which the mterial is worked in subsequent shaping operations, and using high press. water for the descaling operation. Pref. the operation is carried out at 1,100-500 degrees C and the material is subsequently slowly cooled down. The method overcomes the shortcomings of the two conventional methods of descaling in which using metal granules which are impinged on the surface fine cracks tend to be closed up, or in the alternative method of etching the defects are very difficult to see due to the effects of the acid on the surface.