High-Speed Machining of Malleable Cast Iron by Various Cutting Tools Coated by Physical Vapor Deposition

The coating material of a tool directly affects the efficiency and cost of machining malleable cast iron. However, the machining adaptability of various coating materials to malleable cast iron has been insufficiently researched. In this paper, turning tests were conducted on cemented carbide tools with different coatings (a thick TiN/TiAlN coating, a thin TiN/TiAlN coating, and a nanocomposite (nc) TiAlSiN coating). All coatings were applied by physical vapor deposition. In a comparative study of chip morphology, cutting force, cutting temperature, specific cutting energy, tool wear, and surface roughness, this study analyzed the cutting characteristics of the tools coated with various materials, and established the relationship between the cutting parameters and machining objectives. The results showed that in malleable cast iron machining, the coating material significantly affects the cutting performance of the tool. Among the three tools, the nc-TiAlSiN-coated carbide tool achieved the minimum cutting force, the lowest cutting temperature, least tool wear, longest tool life, and best surface quality. Moreover, in comparisons between cemented-carbide and compacted-graphite cast iron machined under the same conditions, the wear mechanism of the coated tools was found to depend on the cast iron being machined. Therefore, the performance requirements of a tool depend on multiple factors, and selecting an appropriately coated tool for a particular cast iron material is essential.

Tellurium Effect on ASTM A 220 Graphite Malleable Cast Iron

The result of investigation of tellurium malleable cast iron are presented in the paper. Various small quantity of tellurium are added in the ladle before pouring molten metal. The main aim of investigation was determination of the influence composition of tellurium on graphite microstructure and mechanical properties. In addition, the final mechanical property of composition determined by hardness measurements. The favourable influence of the addition of tellurium into malleable cast iron molten metal on the tested properties after annealing as well as an percentation of graphite structure from 2% up to 6.5% and increase hardness from 38 HRc up to 43 HRc

Sorting nipple castings from malleable cast iron from the result of measuring their residual magnetization

The physical principles of magnetic control of the structure of malleable cast iron compact castings are summarized. It reports on the technical features and mode of operation of the automated instrument used for control. The features of formation of remanent magnetization of unhealed castings of nipples from malleable cast iron with bleached surface layer, features of the influence of changes in the layer thickness on the result of magnetization of the castings are established. A criterion for sorting castings with thickness of the bleached layer was developed based on the result of measuring its residual magnetization a given. Recommendations on its use when adjusting the rejection limit for automated magnetic sorting of castings by structure at the Minsk plant of heating equipment are given.

Evolution of unregulated forms of graphite inclusions in graphitized structural cast iron

The evolution influence of the graphite form (from a platetype form to a globular one) upon structural cast iron properties was analyzed and grounded, there were also considered cast iron peculiarities and prospects of their commercial application is estimated. For castings production the expediency of rational application of unregulated graphitized cast iron with the intermediate transitional morphology of graphite inclusions instead of grey iron high grades with lamellar graphite (GI 30, GI 35) and malleable cast iron is shown. The appropriate use substantiation of mentioned cast iron types taking into account their peculi-arities is shown.