Relationship Between Some Physico-Mechanical Properties and Numerical Indexes of Graphite Shape in Compacted-Vermicular Graphite Cast Irons

Abstract

The main purpose of this paper is to present some data on the mechanical and physical properties of compacted-vermicular graphite cast iron and to give a reasonable interpretation to the characteristics by using numerical indexes indicating the shape of graphite flakes in the structure. After describing the preparation of the material and a new method for measuring thermal diffusivity of the iron, the influence of kind and amount of alloy added for treatment and of cooling rate upon the graphite shape is discussed by using the indexes of the structure. The thermal diffusivities and mechanical characteristics such as tensile strength and hardness are shown as functions of the indexes to clarify the relationship between them. Furthermore, the present indexes are compared with those proposed earlier to find which is most suitable for the cast iron treated in this work. Authors propose a definition of compacted-vermicular graphite cast iron, which is reasonable from the physico-mechanical point of view, and also show some typical mechanical properties and measures required to produce such cast iron with desirable features.

Characterization Of Graphite Particle Shape In Spheroidal Graphite Iron Using A Computer-Based Image Analyzer

“…For graphite particles in the hue of compacted/vermicular, near-nodule and spheroids in cast iron, several parameters have been defined, each serving different purposes in relation to particular properties or features [7][8][9]. In the special case of SGI, what is needed is a good descriptor that would give a vivid or an all encompassing categorization (or characterization) of deviations from a completely spheroidal graphite to forms such as spiky, chunky, fern-like, doughnut, cabbage, stubby, wormy, crab, octopus, irregular spheroids, near/semi-nodule, etc.…”

Elevated temperature thermal conductivities of some as-cast and austempered cast irons

“…The flake form is not optimal for strength, and thus grey cast iron grades have generally lesser mechanical properties. Compacted graphite cast irons (CGI) often have thermal and mechanical properties in between grey and ductile irons due to the graphite shape, effectively being between spherical nodules and lamellae due to the incomplete spheroidising process [6][7][8][9]14]. LGI and CGI have traditionally been of interest as engine component materials [15,16] due to being good compromises mechanically and thermally.…”

Analysis of Localized Plastic Strain in Heterogeneous Cast Iron Microstructures Using 3D Finite Element Simulations

“…In the field of shape analysis, it is common practice to specify one global measure of the graphite particle and one concerning the morphology to determine different microstructural features [4]. Several parameters have been defined over the years that serve the purpose of defining particular properties specifically for compacted and lamellar graphite inclusions [5]. Several methods have been developed that propose to characterize microstructures, see e.g.…”