21NiCrMo2 Çeliğinin Korozyon Hızına Borlama İşleminin Etkileri

21NiCrMo2 çeliği korozyona dayanımı düşük bir çeliktir. Bu çalışmanın amacı, katı borlama yöntemi ile 21NiCrMo2 çeliğinin korozyon dayanımı artırmaktır. 21NiCrMo2 çeliği 700oC sıcaklık ve 4, 8, 12 ve 16 saat sürelerde borlama işlemine tabi tutulmuştur. Borlama ajanı olarak yerli borlama ajanı olan Baybora-1 kullanılmıştır. Numunelerin metal-borür tabakası ve geçiş tabakasının morfolojisi SEM cihazı ile belirlenmiştir. Borlanmış numunelerin yüzeyinde oluşan metal-borür tabakasının faz analizleri XRD cihazı ile yapılmıştır. Borlanmış ve borlanmamış çelik numunelerin korozyon deneyi ASTM G31-72 standardına göre sıcak sülfirik asit çözeltisinde yapılmıştır. Numunelerin korozyon dayanımı ağırlık kaybı yöntemi ile belirlenmiştir. Borlanmış numunelerin korozyon dayanımı 323 mm/yıl iken borlanmamış numunenin 491 mm/yıl olduğu belirlenmiştir.

Anahtar Kelimeler:

Borlama, Seramik metal-borür tabaka, korozyon, 21NiCrMo2 çelik

Effects of Boronizing on Corrosion Rate of 21NiCrMo2 Steel

21NiCrMo2 steel is a steel with low corrosion resistance. The aim of this study is to increase the corrosion resistance of 21NiCrMo2 steel by solid boriding method. 21NiCrMo2 steel was borided at 700oC and for 4, 8, 12 and 16 hours. Baybora-1, a domestic boronizing agent, was used as the boronizing agent. The morphology of the metal-boride layer and the transition layer of the samples were determined by SEM device. The phase analyzes of the metal-boride layer formed on the surface of the boronized samples were made with the XRD device. Corrosion test of boronized and non boronized steel samples was carried out in hot sulfuric acid solution according to ASTM G31-72 standard. The corrosion resistance of the samples was determined by the weight loss method. While the corrosion resistance of boronized samples was 323 mm/year, it was determined that the non-boronized sample was 491 mm/year.

Keywords:

Boronizing, Ceramic metal-boride layer, corrosion, 21NiCrMo2 steel,

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