Microstructural characterization, boriding kinetics and tribo-wear behavior of borided Fe-based A286 superalloy

Microstructural evolution and mechanical behaviour of boronized martensitic stainless steels

“…Since boronizing is a diffusion-based thermochemical process, the rates at which boron diffusion progresses within the substrate and the alloying elements diffuse during the formation of borides, are unequal. Owing to Kirkendall effect, vacancies are interjected at the boronized layer/ substrate interface [11,13]. With time, these vacancies accumulate to form small voids and further grow into pores.…”

“…The hardness of the boronized layer was measured using Vickers microhardness tester by applying a load of 100 g for 20 s. On the cross-section of the polished sample, 10 readings were taken and average is reported along with standard deviation. Fracture toughness of boronized layer was estimated using micro-indentation induced fracture method by applying a load of 2.981 N for 10 s. After indentation, crack length ‘c’ and diagonal ‘a’ were measured and the fracture toughness is calculated using (1) [11]. where E, H, P and c are Young's modulus (GPa), hardness (GPa), applied load (N) and crack length (m), respectively.…”

“…However, due to larger substitutional Cr (atomic radius = 1.66 Å) atoms as compared to Fe (1.56 Å), it is difficult for the B (0.87 Å) atoms to occupy the interstitial space. This restricts the flow of B atoms through the outer boronized layer and facilitates the growth and thickening of FeB phase and hence higher activation energy is required for nucleation of Fe 2 B phase [11].…”

Evaluation of pitting susceptibility and tribocorrosion behaviors of AISI 304 stainless steel in marine environments

“…The Poisson ratio of the alloy was taken as 0.29 with the elastic modulus 193 GPa, and the contact stress was calculated according to Hertzian contact theory as 1.53 GPa and 1.75 GPa for 5 N and 7.5 N, respectively, which was done similarly by several researchers in the literature. 12,26 The normal loads were applied through a 6 mm linear sliding stroke with a 74 rpm frequency, and the total sliding distance was 13.32 m. The applied loads were selected to evaluate previous studies and understand the load effects on pitting susceptibility and tribocorrosion behavior of AISI 304, considering the Hertzian Contact Theory.…”

Tribological Study and Surface Characterization of a Boron Coating Applied to an AISI L6 Steel Used in the Agricultural Area

“…In the roughness studies it is observed that the base material has a roughness of Sa = 0.13±0.02 µm, Sq = 0.17±0.02 µm and Sz = 1.28±0.26 µm, for the thermochemical treatments it is observed that the roughness Sa, Sq and Sz they increase as the incubation time increases, obtaining the maximum roughness for the treatment with 3 h of incubation, showing that the roughness for the boriding process is not homogeneous and increases for each treatment [8], figure 2a; Likewise, research by different authors has shown that the thickness and mechanical properties increase as the incubation time and temperature increase [9,10].…”