Nodularizer for nodular iron with thick section

Abstract

The invention discloses a nodularizer for nodular iron with a thick section, and belongs to casting alloys. The nodularizer consists of elements of magnesium, silicon, barium, calcium, rare earth, antimony and iron, wherein the rare earth consists of cerium and yttrium; the nodularizer comprises 6 to 10 weight percent of magnesium, 40 to 48 weight percent of silicon, 5 to 6 weight percent of barium and calcium, 3 to 5 weight percent of rare earth, 0.4 to 0.7 weight percent of antimony and the balance of iron; the ratio of antimony to the rare earth is (8-14): 100; the 3 to 5 percent of rare earth contains 1.5 to 2.5 percent of cerium and 1.5 to 2.5 percent of yttrium; and the ratio of antimony to the cerium is (20-40): 100. After the nodularizer is applied, the nodular iron with the thick section can achieve satisfactory nodulizing effect within the curing time of 240 minutes, and the nodularizer particularly can inhibit graphite distortion in the nodular iron with the thick section.

Description

technical field [0001] The invention relates to a nodulizer, in particular to a nodulizer for treating thick and large section ductile iron. Background technique [0002] Thick and large-section ductile iron castings have excellent mechanical properties and economic advantages. They are important basic components of national major technical equipment and play a very important role in the national economy. With the advancement of ductile iron production technology and the continuous emergence of new application fields, the market for ductile iron parts with thick and large cross-sections is becoming more and more prosperous, and its typical representative is the heavy 100-ton nuclear spent nuclear fuel ductile iron storage and transportation container. However, due to its too thick section, the cooling rate is slow and the solidification time is long, and graphite distortion (such as fragmented graphite), spheroidization decline, reduction in the number of graphite spheres, l...

AI Technical Summary

Problems solved by technology

At present, the commonly used spheroidizers in China usually contain a certain amount of rare earth and antimony elements, but the contents of rare earth and antimony elements are not the same, so it is easy to cause unstable spheroidization effect. When the wall thickness exceeds 500mm, it is not conducive to controlling graphite distortion. It brings difficulties to the production of ductile iron parts with thick and large sections