Method for eliminating contraction stomata around iron crankshaft core of iron sand lined steel casting ball

Abstract

The invention relates to a method for the shrinkage cavities surrounding a crankshaft core of a sand-coated casting ductile iron of an iron mold; the method includes the following steps: a, the chemical components of an iron liquid are adjusted for leading the content of CE to be equal to or more than 4.25 percent and leading the content of SC to be equal to or more than 1 percent, the optimal content of CE is between 4.6 and 4.7; b, the smallest wall thickness of the manufactured iron mold is not less than 30mm and the back surface is not hollowed; c, a maximized iron core is adopted, thus maintaining the thinnest location of a sand-coated layer to be not less than 2.5mm under the situation of being capable of taking out the iron core; d, the casting temperature is controlled between 1400 and 1450 DEG C. By adopting the method, the generated shrinkage cavities surrounding the crankshaft core of the sand-coated casting ductile iron of the iron mold are eliminated, the qualified rate of a product is increased by 5 to 30 percent, the casting temperature is lowered, the service life of an electric furnace is prolonged, energy is saved and the energy consumption is reduced.

Description

technical field [0001] The invention belongs to a casting method, and in particular relates to a method for eliminating shrinkage pores around a nodular iron crankshaft core cast with sand-covered iron moulds. Background technique [0002] The sand-covered iron casting process has become a typical process commonly used in the production of high-strength ductile iron crankshafts. The crankshaft produced by this process has the advantages of good mechanical properties, beautiful appearance, and high yield of materials, but at the same time, this process also has the problem that shrinkage defects often occur around the crankshaft core. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a method for eliminating the shrinkage holes around the iron mold sand-covered casting ductile iron crankshaft core, thereby eliminating the shrinkage pores generated around the iron mold sand-covered casting ductile iron crankshaft cor...

AI Technical Summary

Problems solved by technology

The crankshaft produced by this process has the advantages of good mechanical properties, beautiful appearance, and high material yield, but at the same time, this process also has the problem of shrinkage holes around the crankshaft core.