Thank you all for your replays. For more details and clarification about the problem I attached three microstructure test results (two types of cracks were found)http://files.engineering.com/getfile.aspx?folder=9b714466-8f35-47ba-ae24-7008a56a76fd&file=image.jpg
I'm working as a quality control engineer in EZDK company (Egypt) which produce deformed steel rebars. We use QTB technology for producing rebars. Recently, discontinuous cracks appeared on the Deformed 12 mm rebars surface. Micro structure test showed that the crack depth is about 0.8 mm. I...