Investigating the influence of thermomechanical variables on ridging in aisi 430 stainless steel

• Main Author: Matthews, Ryan
• Other Authors: Knutsen, Robert D
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2014
• Subjects: Mechanical Engineering
• Online Access: http://hdl.handle.net/11427/5508

Includes bibliographical references. === The phenomenon of ridging is known to occur in most ferritic stainless steels and is manifested during deformation of sheet material. It results in the formation of a corrugated profile with ridges always elongated in the rolling direction of the sheet and are typically around 1 mm in wavelength. The formation of a ridged profile, while not having a detrimental effect of the mechanical properties, results in the product having an unatractive surface finish. Thus there is a drive to find a thermomechanical process to minimise the severity of ridging in the final sheet product. In this regard, the purpose of this investigation was to establish the influence of three thermomechanical (TMP) variables on the ridging severity. The samples in this investigation represented: two zones of the initial starting structure, with equiaxed of solunar grains; four hot rolling finish temperatures (HRFT), 700°C, 800°C, 900°C and 1000°C; and two colling methods after hot rolling, quench and slow cool versus slow cool. Each sample completed the TMP cycle, was elongated to 20% strain and the topography on the surface measured and compared.