Investigation of the Effect of Lubricant on Roughness Transfer with Temper Rolling to DC04 Grade Sheet Materials

Öz

In the skin-pass rolling process, which is the last stage of the cold rolling production process, roughness is transferred to the surface of sheet materials with specially roughened rolls. In particular, sheet materials used in the automotive field are required to have a roughness value provided that they are in a standard range and have a homogeneous distribution. Thanks to the roughness value that is homogeneously distributed and meets the standards, the forming ability and paint adhesion of sheet materials are improved. In this study, the effect of lubricant (mineral oil) on roughness transfer by skin-pass rolling to DC04 grade sheet materials, which are used extensively in the automotive and white goods industry, was experimentally investigated. It was concluded that less roughness was transferred under the conditions where the lubricant was used in the experiments conducted with a 500 µm reduction. Also, when 3D area scan images and material ratio curves (MRC) were examined, a more homogeneous roughness profile was obtained compared to dry conditions. It was concluded that the lubricant both reduced the rolling force and caused a decrease in roughness transfer by forming a film layer on the surface, and a homogeneous roughness profile transfer to the material surface.

Anahtar Kelimeler

• Skin-pass (Temper) rolling
• Roughness transfer
• Lubricant
• DC04 grade sheet materials

DC04 Kalite Sac Malzemelere Temper Haddeleme ile Pürüzlülük Transferinde Yağlayıcının Etkisinin İncelenmesi

Öz

Soğuk haddeleme üretim sürecinin son aşaması olan temper haddeleme işleminde sac malzemelerin yüzeyine özel pürüzlendirilmiş merdaneler ile pürüzlülük transfer edilir. Özellikle otomotiv alanında kullanılan sac malzemelerin, standart aralıkta ve homojen dağılım göstermesi kaydıyla bir pürüzlülük değerine sahip olması istenir. Homojen dağılan ve standartları karşılayan pürüzlülük değeri sayesinde sac malzemelerin şekillendirme kabiliyeti ve boya yapışma özelliği iyileşmiş olur. Bu çalışmada otomotiv ve beyaz eşya sektöründe yoğun bir şekilde kullanılan şekillendirme kabiliyeti yüksek olan DC04 kalite sac malzemelere temper haddeleme ile pürüzlülük transferinde yağlayıcının etkisi (mineral yağ) deneysel olarak incelenmiştir. 500 µm ezme miktarında yapılan deneylerde yağlayıcı kullanılan şartlarda daha az miktarda pürüzlülük transfer edildiği sonucuna varılmıştır. Ayrıca 3D alan tarama görüntüleri ve malzeme oranı eğrileri (MRC) incelendiğinde kuru şartlara göre daha homojen bir pürüzlülük profili elde edilmiştir. Yağlayıcının hem haddeleme kuvvetini azalttığı ve yüzeyde bir film tabaka oluşturarak pürüzlülük transferinin azalmasına, hem de malzeme yüzeyine homojen bir pürüzlülük profili transferi meydana gelmesine sebep olduğu sonucuna varılmıştır.

Anahtar Kelimeler

• Temper haddeleme
• Pürüzlülük transferi
• Yağlayıcı
• DC04 kalite sac malzemeler

Kaynakça

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