Title

HOT ROLLING SURFACE QUALITY ISSUES

HOT ROLLING SURFACE QUALITY ISSUES

Authorship

Jansto, Steven G.; Stalheim., Douglas G.

Jansto, Steven G.

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Stalheim., Douglas G.

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DOI

10.5151/2594-5297-22581

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Abstract

Surface quality issues in hot rolled plate and coil structural steel is a challenge for every steel mill around the world. Proper process set up along with overall processing parameters must be satisfactorily implemented in order to minimize surface quality issues in hot rolled coil, plate and sheet steels. Surface quality issues may initiate from various steelmaking, casting, reheating, hot rolling and overall plate/coil handling sources. Because sources of surface quality issues can be numerous, often, the appropriate analysis and identification of the root causes is incorrect resulting in ineffective corrective actions. A proper understanding of the potential sources of surface quality issues, a proper investigative root cause analysis, and in many cases, a simple process of elimination result in the successful implementation of the proper corrective action. There are fundamental operational, process set up and metallurgical parameters that are universal regardless of steelmaking, casting, rolling and overall mill configuration that need to be understood and controlled to minimize surface quality issues. The interaction of these factors governs the resultant hot roll surface quality and mechanical properties. It is extremely important that the proper identification of surface quality issues is determined so that the proper corrective actions can be employed. This paper will focus on common hot rolling defect characteristics, proper identification of such defects, cause and effect relationships, and corrective actions. Examples of actual cases will be presented.

Surface quality issues in hot rolled plate and coil structural steel is a challenge for every steel mill around the world. Proper process set up along with overall processing parameters must be satisfactorily implemented in order to minimize surface quality issues in hot rolled coil, plate and sheet steels. Surface quality issues may initiate from various steelmaking, casting, reheating, hot rolling and overall plate/coil handling sources. Because sources of surface quality issues can be numerous, often, the appropriate analysis and identification of the root causes is incorrect resulting in ineffective corrective actions. A proper understanding of the potential sources of surface quality issues, a proper investigative root cause analysis, and in many cases, a simple process of elimination result in the successful implementation of the proper corrective action. There are fundamental operational, process set up and metallurgical parameters that are universal regardless of steelmaking, casting, rolling and overall mill configuration that need to be understood and controlled to minimize surface quality issues. The interaction of these factors governs the resultant hot roll surface quality and mechanical properties. It is extremely important that the proper identification of surface quality issues is determined so that the proper corrective actions can be employed. This paper will focus on common hot rolling defect characteristics, proper identification of such defects, cause and effect relationships, and corrective actions. Examples of actual cases will be presented.

Keywords

Defect identification; Hot rolling; Root-cause analysis; Surface quality.

Defect identification; Hot rolling; Root-cause analysis; Surface quality.