黒鉛球状化の理論
スポンサーリンク
概要
- 論文の詳細を見る
Mineral graphite occurs in the following shapes (Dana's book): (1) Six-sided tabular or Slaty. (2) Foliated, Scaly, Laminae. (3) Columnar. (4) Radiated. (5) Granular. (6) Earthy. (7) Globular (rare). (8) Vein (rare). In cast iron the sections of (5), lump graphite, and of (2), flake graphite, are most predominantly observable. I think the graphites of various shaps grew all from nuclear small lump ones up. Six-sided columnar crystals will result under the conditions of free growth. But as there exists incessant relative motion between graphites and molten metal the glaphites, which are very weak at high temperatures, will break by slipping along the basal plane and the edges will be smoothed. Round slaty graphites are thus to be formed. Theae slaty crystals, however, become all curved because graphite is very flexible and non-elastic at high temperatures (Dana's book). The sections of these curved slaty crystals are shown as flake graphites under the microscope. The crystals which do not slip grow into columnar or granular shape up, which sections are shown as lump graphites. These lump graphites (extremely flexible and non-elastic at high temperatures) have tendency to become globular due to their own surface tension. In ordinary case, however, surface tension is not sufficiently large to make globular graphites. When Mg- or Ce- treated molten cast iron solidifies the disolved Mg or Ce becomes super-saturated and separates as vapour out, and the vapour is instantly adsorbed by growing graphites. The surface tension of the graphites is assumed to increase by the adsorption making the crystals globular. Only minute addition of Mg or Ce may be sufficient for the vapour-adsorption modifying the surface tention. Low content of Sand P are desirable for the cast iron as these elements lessen the quantity of adsorption. The fact that the Mg- treated molten iron which will become globular on inoculation using Fe-Si becomes flake graphite cast iron on inoculation using graphite powder may be explaind by previous adsorption of Ce or Mg vapour by added graphite powder. Mg and Ce are first dissolved in molten metal and separate later on solidifing out. All observed facts can be explained by this theory.
- 日本鋳造工学会の論文
日本鋳造工学会 | 論文
- 薄板試験片による球状黒鉛鋳鉄の引張特性評価
- スモールパンチ試験による薄肉球状黒鉛鋳鉄のじん性評価
- 金属疲労の基礎知識
- 鋳造シミュレーションによる鋳ぐるみ接合の方案検討とその実験的検証
- 鋳ぐるみによる接合と複合化