Vermiculizer for thin-wall cast iron and melting method thereof

Abstract

The invention discloses a vermiculizer for thin-wall cast iron and a melting method thereof, and relates to a cast iron vermiculizer. The melting of the vermiculizer comprises the following steps: 1, examining before smelting; 2, charging before opening a furnace and transmitting power; 3, smelting and charging; 4, discharging from the furnace and casting; 5, crushing; and 6, checking, identifying and storing, wherein the obtained vermiculizer comprises 15 to 25 percent of rare earth (RE), 35 to 45 percent of silicon (Si), 2.5 to 4.5 percent of magnesium (Mg), 2 to 4 percent of calcium (Ca), 1.5 to 3.5 percent of zinc (Zn), 0.6 to 1.4 percent of magnesium oxide (MgO) and 20 to 40 percent of balance of ferrum (Fe) or inevitable impurity. The vermiculizer has the advantages of relatively simple and stable vermiculizing treatment process, good dissolubility, relatively wide vermiculizing range, no stirring, no desulphurization treatment for raw melted iron, and suitability for producing the thin-wall cast iron in low-sulfur and high-sulfur states.

Description

Technical field: [0001] The invention relates to a cast iron vermicular agent, in particular to a vermicular agent for thin-walled cast iron and a melting method thereof. Background technique: [0002] Vermicular iron is a kind of cast iron with worm-like graphite, its mechanical properties are between gray iron and ductile iron, but the thermal shock fatigue resistance of vermicular iron exceeds that of ductile iron and gray iron, and its compactness and pressure fatigue resistance are better than that of spherical iron. Iron and high-grade gray cast iron, and most suitable for pressure-resistant, leakage-resistant hydraulic castings, so vermicular graphite cast iron is used on engine cylinder blocks and cylinder heads to improve the performance of internal combustion engines and exhaust gas purification, and at the same time increase the heat and Force loading (see; Steve Dawson, Compacted Graphite Iron - Material for Modern Diesel Engine Blocks and Heads). [0003] The v...

AI Technical Summary

Problems solved by technology

The vaporization of magnesium in molten iron can accelerate the diffusion and dissolution of the creeping agent. Due to its strong self-boiling ability, it does not need to be stirred and is easy to operate. However, titanium interfering elements are easy to pollute the furnace charge, causing great harm to the use and management of casting returned charge. Difficult, and these interfering elements are easy to form carbides during the solidification of molten iron, which seriously affects the machining and cutting performance of castings (see; Casting Branch of the Chinese Mechanical Engineering Society, Casting Manual Volume 1, Second Edition "Cast Iron")