Effect of Carbon Content and Boronizing Parameters on Growth Kinetics of Boride Layers Obtained on Carbon Steels

Abstract

Boronizing is a thermochemical treatment performed to produce hard and wear-resistant surface layers. In order to control the process and obtain boride layers with the desired properties, it is very important to know how the boronizing parameters and the chemical composition of the treated steel affect the boronizing. The aim of the present study is to investigate the influence of carbon content in carbon steels, boronizing temperature, and boronizing duration on the growth kinetics of boride layers. For this purpose, three carbon steels (C1y5, C45, and C70W2) were boronized in solid medium. The experimental results show that there is a linear relationship between the carbon content and the activation energy values, and between the carbon content and the frequency factors. In addition, a statistical analysis was performed to determine the contribution of each factor. The ANOVA showed that boronizing temperature has the highest effect on the boride layer thickness, followed by the boronizing duration, while the carbon content of the steel has the least effect on the boride layer thickness. Based on a regression model, an empirical equation was derived to estimate the thickness of the boride layer on carbon steels as a function of carbon content, boronizing temperature, and duration.

Effect of Boronizing on the Microstructure and Mechanical Properties of CoCrFeNiMn High-Entropy Alloy

“…Previous studies have mainly investigated the growth kinetics of steel and its alloys. Andrijana Milinović et al [ 33 ] investigated the growth kinetics of different steels, and the results showed that the frequency factor D 0 and diffusion activation energy Q of elemental boron in C15 steel are 3.17 × 10 −4 m 2 /s and 194.80 kJ/mol, respectively. Figure 3 shows the BL and the whole layer thickness as a function of time.…”

Improving the Surface Properties of an API 5L Grade B Pipeline Steel by Applying the Boriding Process. Part I: Kinetics and Layer Characterization

“…This is the typical morphology formed on lowcarbon steels when they are exposed to the boriding process [24,25]. Different researchers have reported that the characteristic saw-tooth boride layer morphology is seen in low-alloy steels, unalloyed low-carbon steels, and pure iron [27,41,42]. The layers' thickness ranged from approximately 30 to 218 µm for the samples exposed to 850 • C for 2 h and the samples exposed to 1000 • C and 6 h, respectively.…”

Analysis of the Boronizing Process of High-vanadium Alloy Steel

“…The relationship between the thickness of the boronizing layer and the boronizing temperature is shown in Fig 2 . It is shown that the boronizing layer thickness increased with the increase in boronizing temperature. With the extension of boronizing time, the boronizing layer thickness is nonlinear with the increase of the boronizing temperature [8]. Boriding is a typical reaction-diffusion process.…”