Publication: Toz enjeksiyon kalıplama metodu ile üretilen AISI-420 martenzitik paslanmaz çeliklere niyobyum ilavesinin etkisi : mikroyapı, mekanik ve korozyon özellikleri
Abstract
Bu çalışmada, üstün mekanik özellikler ve orta düzey korozyon özelliklerinden dolayı AISI-420 martenzitik paslanmaz çelikler geleneksel üretim yöntemleri olan döküm ve dövme yöntemi dışında karmaşık yapılı, yüksek performanslı ve çok sayıda parça üretimine imkan tanıyan Toz Enjeksiyon Kalıplama yöntemi ile niyobyum ilave edilerek üretimi gerçekleştirilmiştir. Üretilen numuneler mikroyapı, mekanik ve korozyon özelliklerine niyobyum etkisi karakterizasyon çalışmaları ile detaylı olarak irdelenmiştir. Bu amaçla, TEK prosesi için uygun AISI-420 küresel paslanmaz çelik tozları Sandvik Osprey Ltd. Firmasından temin edilmiş ve uygun viskozite değerlerine ulaşabilme gayesi ile belirlenen oranlarda polimerik bağlayıcılar ile karıştırılmıştır. Besleme stoğunun kalıplanabilirliğinin belirlenmesi amacıyla reometre cihazı kullanılarak besleme stoklarının akış davranışları belirlenmiştir. Standart ölçülerde kalıplanan besleme stoğuna, kalıplama sonrasında solvent ve ısıl olmak üzere iki farklı aşamada bağlayıcı giderme işlemi uygulanmıştır. Bağlayıcı giderme aşaması sonrasında numuneler farklı sinterleme şartlarında sinterlenmiştir. Sinterleme sonrasında mikroyapısal, mekanik ve korozyon dayanımının belirlenmesi için karakterizasyon işlemleri gerçekleştirilmiştir. Elde edilen sonuçlara göre, Toz enjeksiyon Kalıplama üretim parametrelerinin AISI 420 + Nb numune özelliklerine etkileri incelenmiştir. Bulgular literatür verileri ışığı altında incelenmiş ve yorumlanmıştır.
In this study, due to its superior mechanical properties and moderate corrosion characteristics, AISI-420 is one of the most diversified production methods in recent years except the casting and forging method which is the traditional production methods of martensitic stainless steel. It is aimed to produce with the addition of niobium AISI 420 SS via Powder Injection molding method and to perform characterization processes such as microstructural, mechanical and corrosion. For this purpose, AISI-420 spherical stainless steel powders which suitable for the Powder Injection molding process were obtained from Sandvik Osprey Ltd and mixed with polymeric binders at determined rates to achieve the appropriate viscosity values. The flow behaviors of feed stocks were determined by using rheometer to determine the moldability of feed stock. Batch removal process was carried out in two different stages: the feedstock, which was molded in standard sizes, and the solvent and heat after molding. Samples were sintered under different sintering conditions after the coupling removal step. After sintering, characterization processes were performed to determine the microstructural, mechanical and corrosion resistance. According to the results, the effects of addition niobium to AISI420 via Powder Injection Molding production parameters on sample properties were investigated. The findings were examined and interpreted in the light of the literature.
In this study, due to its superior mechanical properties and moderate corrosion characteristics, AISI-420 is one of the most diversified production methods in recent years except the casting and forging method which is the traditional production methods of martensitic stainless steel. It is aimed to produce with the addition of niobium AISI 420 SS via Powder Injection molding method and to perform characterization processes such as microstructural, mechanical and corrosion. For this purpose, AISI-420 spherical stainless steel powders which suitable for the Powder Injection molding process were obtained from Sandvik Osprey Ltd and mixed with polymeric binders at determined rates to achieve the appropriate viscosity values. The flow behaviors of feed stocks were determined by using rheometer to determine the moldability of feed stock. Batch removal process was carried out in two different stages: the feedstock, which was molded in standard sizes, and the solvent and heat after molding. Samples were sintered under different sintering conditions after the coupling removal step. After sintering, characterization processes were performed to determine the microstructural, mechanical and corrosion resistance. According to the results, the effects of addition niobium to AISI420 via Powder Injection Molding production parameters on sample properties were investigated. The findings were examined and interpreted in the light of the literature.