17-4PH paslanmaz çeliğin oyuk korozyon davranışının fraktal boyut ve Shannon entropi ile karakterizasyonu

Öz

Bu çalışma, sulu klorür çözeltisinde farklı sertlik seviyelerine kadar termal olarak yaşlandırılmış 17-4 PH paslanmaz çelik alaşımlarında oyuk korozyonu oluşumu ve gelişim davranışını incelemektedir. Çözeltide %10 oranında klorür ve %30 oranında hidrojen peroksit bulunmaktadır ve numuneler sabit oda sıcaklığında tutulurken farklı sürelerde bu aşındırıcı ortama maruz bırakılmıştır. Çalışmada, farklı sertlik düzeylerine sahip numunelerde maruz kalma süresinin etkileri ve oyuk gelişimi araştırılmıştır. Bu çalışmada kullanılan yöntemler arasında ağırlık kaybı ölçümleri, makro gözlemler, taramalı elektron mikroskobu (SEM) analizleri, elektrokimyasal testler, fraktal ve shannon entropi değerlendirmeleri yer almaktadır. Oyuk korozyon potansiyeli, aşınma süresi boyunca potansiyodinamik polarizasyon yöntemiyle izlenmiştir. Elde edilen bulgular, oyuk korozyonu potansiyelinin yaşlandırma sıcaklığına bağlı olarak değiştiğini ve malzemenin sertliğiyle ilişkili olduğunu göstermektedir. Aşınma sonucunda elde edilen numuneler üzerinde yapılan görüntü işleme ve fraktal boyut analizlerinden elde edilen bilgilere dayanarak oyuk korozyonun aşınma süresi boyunca oluşum ve gelişim davranışları incelenmiştir.

Anahtar Kelimeler

• Klorür çözeltisi
• Isıl işlem
• Oyuk korozyonu
• Paslanmaz çelik
• Fraktal boyut
• Shannon entropi

Characterization of the pitting corrosion behavior of 17-4Ph stainless steel using fractal dimension and Shannon entropy

Öz

This study investigates the initiation and propagation behavior of pitting corrosion in 17-4 PH stainless steel alloys that have been thermally aged to different hardness levels in an aqueous chloride solution. The solution contains 10% chloride and 30% hydrogen peroxide, and the specimens were exposed to this corrosive environment for varying durations while being kept at constant room temperature. The effects of exposure time and pit growth were examined in samples with different hardness levels. The methods employed in this study include weight loss measurements, macro observations, scanning electron microscopy (SEM) analyses, electrochemical tests, and evaluations using fractal and Shannon entropy approaches. The pitting corrosion potential was monitored throughout the exposure period using the potentiodynamic polarization method. The findings indicate that the pitting corrosion potential varies with aging temperature and is related to the material’s hardness. Based on the data obtained from image processing and fractal dimension analysis conducted on the worn samples, the formation and development behavior of pitting corrosion throughout the exposure period were thoroughly examined.

Anahtar Kelimeler

• Chloride solution
• Heat threating
• Pitting corrosion
• Stainless steel
• Fractal dimension
• Shannon entropy

Kaynakça

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