A kind of preparation method of high-strength thin-walled gray iron casting

Abstract

The invention provides a preparation method of a high-strength thin-wall gray iron casting. The preparation method comprises the following steps: (1) smelting; (2) high-temperature refining; (3) inoculation: the tapping temperature of molten iron is controlled to be 1530-1545 DEG C, the inoculation operation is performed in a casting ladle, a SiC-Zr-Fe intermediate alloy is adopted as an inoculant, the mass content of SiC in the SiC-Zr-Fe intermediate alloy is 20-30%, the mass content of elemental Zr is 7-15%, the balance Fe is contained, and the adding amount of the SiC-Zr-Fe intermediate alloy is 0.4-0.55% of the mass of the molten iron; and (4) casting: the casting temperature is controlled to be 1460-1490 DEG C. The preparation method provided by the invention has the beneficial effects that through the specific inoculant, the graphite form is effectively improved and grains are refined; the effect on the improvement of the strength and the hardness of the gray iron casting is remarkable; and meanwhile, the composition of all the elements in the casting is appropriate, and thus the comprehensive performance of the obtained gray iron casting is excellent.

Description

technical field [0001] The invention relates to the technical field of casting, in particular to a method for preparing a high-strength thin-walled gray iron casting. Background technique [0002] Gray cast iron is a type of cast iron in which the carbon is present in the cast iron in the form of flake graphite. Fracture is gray. It has good casting and cutting performance and good wear resistance. Used to manufacture racks, cabinets, etc. Graphite in gray cast iron is flaky, with a relatively small effective bearing area, and the tip of graphite is prone to stress concentration, so the strength, plasticity, and toughness of gray cast iron are lower than other cast irons. But with excellent vibration damping, low notch sensitivity and high wear resistance. [0003] In the prior art, the common way to improve the strength of thin-walled gray iron castings is to adjust the chemical composition, that is, to reduce the carbon content in the casting raw materials, increase th...

AI Technical Summary

Problems solved by technology

The preparation method of this invention can not only prepare high-strength thin-walled gray iron castings, but also has low cost and comprehensive performance better than the national standard of casting grade HT250, but the improvement of its strength is still limited, thus limiting its application range