The Structure and Properties of Iron Alloys With Various Chemical Compositions After Diffusional Boronizing

Abstract

The purpose of the paper was to test how the content of carbon and alloying elements in steels influence the structure and properties of boronized layers. The following grades of steels were used during the tests: C45, C99U, 41Cr4, 42CrMo4, 45SG, 50HS, 60G, and 102Cr6. In the process of boronizing, the two-phase layer of borides of FeB and Fe2B were obtained on the tested steels with a hardness from 1900 HV0.1 for boride FeB to 1600 HV0.1 for Fe2B, irrespective of the chemical composition of the core/substrate. As the kontent of carbon and alloying elements in steels increase, the structure of borides becomes more compact, and the needles are thicker. The richer in alloying elements the core and the more carbon in steel, the thinner is the boride layer. After boronizing, the layer of FeB and Fe2B with a thickness of approx. 110 μm for C45 steel to approx. 90 μm for 102Cr6 steel was obtained. The test results indicate that the brittleness of borides increases in steels with the addition of Cr, and it decreases in steels containing Si and Mn. The highest wear resistance was obtained in steel 102Cr6.

The Structure of Boride Diffusion Coatings Produced on Selected Grades of Structural Steels

“…1). These values were lower than in boride coatings investigated by Petek-Owsiana [13] (about 90-100 µm). EKABOR-2 pack was characterized by lower concentration of boronizing agent.…”

“…In this research selected structural steels were borided at 1000 °C for 2, 4, 6h using EKABOR-2 powder. The effect of process time and substrate chemical composition on borides growth kinetics and their morphology was investigated by many authors [11][12][13][14]. After two hours of boriding, a thin film consisting of acicular precipitates of the Fe2B phase was formed on the surface of all tested steels.…”

“…In our previous research we investigated the formation of boride coatings on selected types of tools steels [9]. There are many references in the analysis of boride coatings formed using expermimental, self-prepared pack mixtures [11][12][13][14][15][16]. In present article we focused on coatings formed using commercially-aviable packs widely used in industry.…”

Testing the Structure and Properties of Steels After Hardfacing and Laser Treatment

“…Three zones are visible: remelted (MZ), heat effect (HAZ), and substrate. In the remelted zone, there is a eutectic structure containing iron borides and martensite [L. 19,20]. The dimensions of the laser tracks in relation to the parameters of the treatment are shown in Fig.…”