| 摘要 |
PCT No. PCT/SE91/00685 Sec. 371 Date Apr. 15, 1993 Sec. 102(e) Date Apr. 15, 1993 PCT Filed Oct. 11, 1991 PCT Pub. No. WO92/06809 PCT Pub. Date Apr. 30, 1992.A method relating to the production of cast iron castings with compacted graphite crystals. The method comprises controlling and correcting the composition of the cast iron melt and securing the necessary amount of structure modifying agent. A sample of the melt is taken with a sample vessel provided with two thermocouples, one positioned so as to be in the centre of the sample and the other positioned so as to be in the vicinity of the vessel wall. The vessel wall contains or is coated with a layer of a substance which will lower the concentration of dissolved elementary magnesium in the melt in the vicinity of the vessel wall by at least 0.0030%. The temperature/time values obtained through two temperature responsive means are recorded. The occurrence of a plateau temperature will provide information as to the precipitation of flaky graphite in the vicinity of the vessel wall, therewith enabling corrections to be made to the concentration of the modifying agent and to ensure the formation of compacted graphite crystal during the whole of the pouring time required in the foundry process concerned. |
