[MW:23512] Re: SURFACE DEFECT IN HOT ROLLED PLATES

Dear Mehdi Vafakhah,

I try to response to your question with a low number of informations. So I can make an assumption: the material has no defects, like segregation and wrong chemical composition.

In this point of view, the reason of these defects is searchable in hot rolling parameters. Especially analyzing the photo 22222.jpg, it's clear that the metal couldn't follow the plastic deformation imposed by the process. So in my opinion defects are due to:

-  temperature too low

-  strain rate too high (attributable to an angular velocity of rolling cylinders too high)

So, unless then problems related to the material, with a correction of these parameters (increase of T and/or decrease of angular velocity of cylinders), it gives to possibility to the steel to follow the imposed plastic deformation, in order to decrease the defects.

Regards

Mattia DE

Il giorno lunedì 14 settembre 2015 09:38:50 UTC+2, Mehdi Vafakhah ha scritto:

Dear experts

Could you help me to identify the these defect. ( attached pictures )

or refer a guide document that provide me more information about hot rolling defects.

best regards.

 

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