21. yüzyılın çalışma yaşamı; değişkenlik, belirsizlik, karmaşıklık ve muğlaklık gibi birçok faktörü içerisinde barındırmaktadır. Günümüz iş ve çalışma dünyası kariyer yaşamını şekillendirmede kendi sorumluluğunu alabilen, yeniliklere uyum sağlayabilen, krizleri fırsata çevirebilen ve proaktif kariyer davranışları sergileyen bireylere ihtiyaç duymaktadır. Bu yüzden okul yaşamından iş yaşamına geçiş sürecinde olan üniversite öğrencilerinin kariyer uyumlarını güçlendiren değişkenlerin açığa çıkarılması önemli görülmektedir. Bu araştırma ile üniversite öğrencilerinin özyeterlik, deneyime açıklık ve keşif duygusu ile kariyer uyumları arasındaki ilişkide proaktif kariyer davranışlarının aracı rolü incelenmiştir. Araştırmanın katılımcılarını 235’i (%69.1) kadın, 105’i (%30.9) erkek olmak üzere toplamda 340 üniversite öğrencisi oluşturmaktadır. Veri toplama araçları olarak “Genel Özyeterlik Ölçeği”, “Merak ve Keşfetme Ölçeği”, “Beş Faktörlü Kişilik Özelliği Ölçeği”, “Proaktif Kariyer Davranışları Ölçeği” ve “Kariyer Uyum Yetenekleri Ölçeği” kullanılmıştır. Verilerin analizi, korelasyon analizi ve bootstrap yöntemine dayalı regresyon analizi ile yapılmıştır. Doğrudan ve dolaylı ilişkileri test etmek için yol analizi kullanılmıştır. İstatiksel analizler sonucunda proaktif kariyer davranışlarının, özyeterlik, deneyime açıklık ve keşif ile kariyer uyumu ile pozitif yönlü ilişkili olduğu ve proaktif kariyer davranışlarının özyeterlik, deneyime açıklık ve keşif ile kariyer uyumları arasındaki ilişkide aracılık etkisine sahip olduğu bulunmuştur. Bireylerin proaktif kariyer davranışlarını geliştirmek, özyeterlik, deneyime açıklık ve keşfetme duygularını güçlendirmek kariyer uyumlarına olumlu katkı sağlayacaktır. Ulaşılan sonuçlar neticesinde çalışmanın güçlü yönleri ve sınırlılıkları tartışılmış, uygulayıcı ve araştırmacılara yönelik önerilerde bulunulmuştur.
Concentrating solar power (CSP) plants with thermal energy storage (TES) face challenges related to stress relaxation cracking (SRC) in molten hot salt tanks. While alloy 347H stainless steel (SS) is commonly employed due to its stress corrosion cracking (SCC) resistance and sufficient mechanical properties, it suffers from SRC in the weld region. This study explores alloy 1.4910 as a potential alternative, known for its superior creep strength and molten salt corrosion resistance. Thermomechanical testing using a Gleeble® 3500 physical simulator reveals promising results for alloy 1.4910 heat affected zone (HAZ) and 16-8-2 filler (ER16.8.2) fusion zone (FZ), with no cracking observed within a 22-hour test period at elevated temperatures ranging from 600 to 800°C and initial true stress conditions of 650 MPa (0.174 strain) for HAZ and 460 MPa (yield strength) for FZ. In contrast, alloy 347H HAZ and matching filler FZ experienced cracking within a few hours at 800°C. Metallurgical characterization and fractography are additionally conducted on cross welded 1.4910 samples with 16-8-2 filler and thermomechanical Gleeble® samples.
Owing to its corrosion resistance, stainless steel is a sustainable alternative to carbon steel as a structural material in challenging seawater environments. Studies on carbon steel indicate that among all marine corrosion zones (i.e., atmospheric zone, splash zone, tidal zone, and immersed zone), the rate of corrosion is particularly high in the splash zone, above the seawater level, due to the recurrent splashing of seawater with high levels of oxygen and chloride content. Nevertheless, the information on the extent of localized corrosion (i.e., pitting and crevice corrosion) on stainless steel in the splash and tidal zones is scarce and, in most cases, limited to standard austenitic grades. In this work, we present the pitting and crevice corrosion results on lean duplex, duplex, and super duplex stainless steels after two years of field exposure in the North Sea (site at Heligoland South Harbour). The standard austenitic grade 1.4404 (316L) was also exposed as a reference material in atmosphere and splash zone conditions. Parallel exposure of coupons in splash, tidal, and immersed zones allows comparison of the extent of corrosion in each zone and enables proper material selection for structural applications in marine environments.
The critical question for use of Duplex stainless steels at elevated temperatures is normally the embrittlement caused by spinodal decomposition of the ferrite, historically referred to as the 475°C-embrittlement, since 475°C is the most sensitive temperature for this phenomenon. Through the years the stainless steel industry has gained a lot of knowledge on kinetics and boundary conditions on how to apply duplex at high temperatures. The maximum operating temperature has been described in different standards, however with different temperatures. One question that earlier also has been discussed is whether the maximum operating temperature actually should be a combination of time and temperature as this phenomenon develops with time. In this paper some historical examinations combined with relatively new data from different welded duplex stainless steel materials will be presented. Properties of both base metal and weld will be covered and their relevance to the design and operation of pressure vessels and piping systems at high temperatures will be discussed.
Structures located in challenging marine environments play a vital role in several sectors, including offshore wind and oil and gas exploration. These environments expose structures to seawater, airborne chlorides from sea spray, and humid coastal regions. Offshore structures are expected to have a long service life due to limited access for inspection and maintenance. Corrosion is one of the major challenges marine structures face due to chloride-rich environments, wet-dry cycles, high humidity, and microbiological attacks. Material selection and protection methods are critical to ensuring reliability, minimizing maintenance, and extending the service life of marine structures. Duplex stainless steels have been widely used in marine environments for their strength and corrosion resistance. Compared to conventional austenitic stainless steels, duplex grades provide high strength in the solution-annealed condition, enabling the design of lighter structures with thinner gauges. Grating systems are often found on offshore installations, from oil and gas rigs to offshore wind farms. and can be costeffectively constructed in duplex alloys. Forta EDX 2304, Forta DX 2205 and Forta LDX 2101 have been successfully installed in seaside environments, where their strength and improved corrosion allowances permit thinner sections and weight savings. Improved localized corrosion resistance in chlorides, meaning increased pit and crevice corrosion resistance, suggests that service life can be greatly improved, and maintenance needs are diminished. The objective of this paper is to share past experiences with duplex gratings in offshore structures and describe the rationale behind the selection of this class of materials.
