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Microstructures of as-polished spheroidal graphite cast iron observed by an optical microscope: (a) SCI-Cu, (b) SCI-CuB, (c) SCI-Mn, (d) SCI-MnB, (e) SCI-Mn 0.5 Cu 0.5 , (f) SCI-Mn 0.5 Cu 0.5 B, (g) SCI-Mn 0.5 Cu 1 , and (h) SCI-Mn 0.5 Cu 1 B.
Source publication
This study examines the impacts of copper and boron in parts per million (ppm) on the microstructure and mechanical properties of spheroidal graphite cast iron (SCI). Boron’s inclusion increases the ferrite content whereas copper augments the stability of pearlite. The interaction between the two significantly influences the ferrite content. Differ...
Contexts in source publication
Context 1
... heat flow difference between the reference pan and the specimen-containing pan was analyzed using a differential scanning calorimeter (TA Instruments SDT600, New Castle, DE, USA) with an alumina 90-uL crucible. The analysis was performed at a heating rate of 10 • C/min from 50 • C to 1300 • C. Figure 1 shows the microstructure images of each specimen before etching with and without the addition of B. Using these images, we measured the graphite size, graphite nodule count, and graphite area using an image analysis program (IMT iSolution DT) and listed the results in Table 2. The graphite size of specimens with B added tended to increase, up to a maximum of 17%. ...
Context 2
... Figure 2 and Table 2, we can observe that the ferrite area fraction of specimens with B added increased. Figure 1. Microstructures of as-polished spheroidal graphite cast iron observed by an optica scope: (a) SCI-Cu, (b) SCI-CuB, (c) SCI-Mn, (d) SCI-MnB, (e) SCI-Mn0.5Cu0.5, (f) SCI-Mn0 (g) SCI-Mn0.5Cu1, and (h) SCI-Mn0.5Cu1B. ...
Context 3
... comparing the microstructure of Mn 0.5 Cu 0.5 and Mn 0.5 Cu 1 specimens with a significant change in the ferrite fraction after being corroded in 3% nital for 10 min, we found that there is a difference in the surface shape of graphite before and after the addition of B, as shown in Figure 3a-d [15]. B, as shown in Figure 3a-d [15]. ...
Citations
... A hardness increase in chill is possible due to the formation of a carbide network. The potential hardness drop can also be expected with the addition of boron due to ferrite promotion, but it is possible to counteract with N and Ti on high-strength GJS [13,14]. These responses are usually not comparable overall, despite the fact that an overall average hardness increase is mostly expected with boron for grey iron. ...
A study was undertaken to investigate the effects of small boron additions on the solidification and microstructure of hypo-eutectic alloyed grey cast iron. The characteristic temperatures upon crystallisation of the treated metal melt were recorded, specifically those concerning small boron addition by using thermal analysis with the ATAS system. Additionally, a standardised wedge test was set to observe any changes in chill performance. The microstructures of thermal analysis samples were analysed using a light optical microscope (LOM) and field emission scanning electron microscopy (FE-SEM) equipped with energy dispersive spectroscopy (EDS), which reveal variations in graphite count number with the addition of boron within observed random and undercooled flake graphite. The effect of boron was estimated by the classical analytical and statistical approach. The solidification behaviour under equilibrium conditions was predicted by a thermodynamic approach using Thermo-Calc. Based on all gathered data, a response model was set with boron for given melt quality and melt treatment using the experimentally determined data. The study reveals that boron as a ferrite and carbide-promoting element under the experimental set shows weak nucleation potential in synergy with other heterogenic nuclei at increased solidification rates, but no considerable changes were observed by the TA samples solidified at slower cooling rates, indicating the loss of the overall inoculation effect. The potential presence of boron nitride as an inoculator for graphite precipitation for a given melt composition and melt treatment was not confirmed in this study. It seems that boron at increased solidification rates can contribute to overall inoculation, but at slower cooling rates these effects are gradually lost. In the last solidification range, an increased boron content could have a carbide forming nature, as is usually expected. The study suggests that boron in traces could affect the microstructure and properties of hypo-eutectic alloyed grey cast iron.
