TİCARİ TWIP900 VE DP600 YÜKSEK MUKAVEMETLİ ÇELİKLERİN OTOMOTİV ENDÜSTRİSİNDEKİ PERFORMANSLARININ KARŞILAŞTIRILMASI

Bu çalışmada, otomotiv endüstrisi için yeni bir malzeme olan TWIP900 çeliğinin mekanik ve şekillendirilebilme özellikleri incelenmiştir. TWIP çelikleri yüksek mukavemet değerlerinin yanında yüksek şekillendirilebilirliğinden dolayı otomotiv endüstrisinin ilgisini çekmektedir. Çarpışma esnasında yüksek miktarda enerjiyi sönümlemeleri de önemli bir avantajdır. En büyük dezavantajları ise sac şekillendirme sonrasında ortaya çıkan geri esneme miktarının oldukça yüksek olmasıdır. Bu çalışma kapsamında çekme ve geri esneme deneyleri yapılarak malzeme davranışı incelenmiş ve otomotiv endüstrisinde yaygın kullanıma sahip DP600 çeliği ile karşılaştırma yapılmıştır. Ayrıca her iki malzeme için akma yüzeyi ve şekillendirilebilme sınır diyagramları modellenerek karşılaştırılmıştır. Elde edilen sonuçlardan TWIP çeliğinin hafifletmeye büyük katkı sağlayacağı fakat geri esneme probleminin çözülmesi gerektiği tespit edilmiştir. Sonlu elemanlar yazılımlarında TWIP çelikleri modellenirken Swift modelinin Backofen ve Hollomon modellerine göre daha doğru sonuçlar verdiği görülmüştür.

Anahtar Kelimeler:

TWIP, DP, Advanced High Strength Steels, springback, hardening models, von Mises, Marciniak–Kuczynski model, forming limit diagram, yield surface

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