Bu çalışmada, Fe(18-X)CrXB2 (X=3,4,5) bileşimine sahip örtülü elektrotlar üretilmiş ve AISI 1010 çeliği üzerine elektrik ark kaynak yöntemi kullanılarak kaplama işlemi gerçekleştirilmiştir. Nihai mikroyapılarda in-situ olarak oluşan ötektik borür fazlarının varlığı gözlemlenmiştir. Bununla birlikte, ötektik altı faz dağılımı gösteren bileşimlerde, başlıca α(Fe-Cr), tetragonal (Fe,Cr)2B, ortorombik (Fe,Cr)2B ve eser miktarda (Fe,Cr)3(C,B) fazlarının varlığı tespit edilmiştir. Alümina bilyeye karşı gerçekleştirilen ileri-geri aşınma testinde, kaplama tabakalarının sürtünme katsayısı değerleri artan yük ile birlikte azaldığı ve 0,844-0,65 arasında değiştiği tespit edilmiştir. Bununla birlikte, sürtünme katsayısının değişimi krom oranından bağımsız olarak hareket ettiği gözlemlenmiştir. Aşınma oranının ise artan krom miktarı ile azaldığı buna karşın artan yük ile arttığı gözlemlenmiştir. Aşınma oranının, en düşük değeri 3N yükte Fe13Cr5B2 bileşimine sahip elektrot için 2,32x10-5 (mm3/m); en yüksek değeri ise 9N yükte Fe15Cr3B2 bileşimine sahip elektrot için 8,16x10-5 (mm3/m) olduğu tespit edilmiştir. Fe(18-X)CrXB2 (X=3,4,5) bileşimine sahip elektrotlar ile kaplanmış yüzey alaşım tabakalarına potansiyodinamik polorizasyon testi uygulanmıştır. Potansiyodinamik polorizasyon testine göre korozyon direncinin artan krom miktarı ile arttığı görülmüştür. Korozyon testine göre, Ikor değerinin artan krom miktarına göre azalarak sırasıyla 1,7x10-4 µA/cm2 ve 6,5x10-5 µA/cm2 ve 3,4 x10-5 µA/cm2 olarak ölçülmüştür. Ekor değerinin ise artan krom miktarı ile arttığı ve sırasıyla -0,119 mV, -0,179 mV ve -0,239 mV değerine ulaştığı tespit edilmiştir.

In this study, the effects of titanium addition on microstructure, hardness, and wear rate of Fe(13-x)TixB7 (x = 0, 1, 2, 3 and 5) based hard surface alloy layers formed by gas tungsten arc (GTA) welding method were investigated. As a result of the microstructure studies and phase analysis, it was determined that the structures of the coating layers consisted of ?-Fe, ?Fe+Fe2B eutectic, ?-Fe+Fe2Ti eutectic and hard TiB2 phases. In the hard surface alloy layer, as the amount of titanium was increased, the TiB2 phase density formed in the system increased and it was observed that rod-like and long sharpedged phases formed from the equiaxed structure. As a result of wear tests performed at different loads, it was determined that the addition of titanium reduces the wear rates in the coating layers. In addition, scanning electron microscopy (SEM) images of the worn surfaces showed that the wear mechanisms were adhesive and oxidative.

This study investigates the decisive role of boron content (0–30 at. %) in the microstructural evolution, phase competition, and tribological performance of Fe-Cr-V-C-B-based hard cladding coatings applied to S235 steel using TIG welding. The integration of experimental characterization (SEM/EDS, XRD) with computational Scheil-Gulliver simulations has revealed the effect of unstable solidification conditions on material behavior. Increasing boron concentration triggered a sharp morphological transition in the matrix structure from a hypoeutectic dendritic form (0B-V) to fine eutectic networks and, ultimately, to a hyper-eutectic composite dominated by coarse-grained VB and M2B primary borides at the 30 at. % B level. The rapid cooling rates characteristic of TIG welding kinetically favored the nucleation of the VB phase, which has a simpler crystal structure, and suppressed equilibrium phases requiring long-range diffusion. This microstructural strengthening provided a linear increase in hardness values from approximately 575 HV to 900 HV; consequently, the resulting rigid boride network formed an effective barrier against the micro-plowing mechanism, reducing the wear rate by approximately 54%. However, tribological analyses showed that a balance between performance parameters must be maintained: while the addition of 30 at. % B maximized hardness, it triggered structural brittleness and third-body wear, increasing the friction coefficient to 0.42. The results confirm that 20 at.% B is the optimal concentration in terms of wear resistance (µ=0.42) and toughness balance and validate Scheil modeling as a reliable prediction tool for alloy design under rapid solidification conditions.

In this study, the effect of W addition to Fe-B based hard surfacing filler alloy was investigated. For this purpose, electric arc electrode was produced by adding 5% and 10% W to Fe17B3 hard surfacing filler compound and hard surfacing alloy welding was applied on AISI 1010 steel substrate. It was observed that hard boride phases were formed in situ in the microstructure formed after the welding process. As a result of XRD analysis, α-Fe and Fe2B phases were detected in Fe-B based coating. It was determined that FeWB phase was also present together with α-Fe and Fe2B phase in Fe-W-B based coatings. As a result of hardness measurements, micro hardness of Fe-B based composition was determined as 303-341 HV while surface hardness was 28 HRC. When 5% and 10% W element was added to the coating compound, hardness values increased and micro hardness values of 470-699 HV and 642-756 HV were reached, respectively. SEM images showed that the wear microstructures were adhesive, abrasive, fatigue and oxidative in character. The friction coefficient values obtained from the wear tests of the coatings were determined to be between 0.55-0.8. Wear rates were measured between 0.8x10-5 - 1.15x10-5 mm3/m.