Methods of Improving the Smelting Quality of Ductile Iron Hot Metal

Abstract

The invention relates to a method for improving smelting quality of molten ductile iron. The method comprises the following steps of: (1), installing a gas permeable brick on the bottom of a molten iron spheroidizing bag for introducing protective gas in; (2), adding a spheroidizing agent into the roasted spheroidizing bag, and using a refining agent to cover; (3), pouring in molten iron for carrying out spheroidizing treatment; (4), blowing in inert gases from the bottom of the molten iron spheroidizing bag after the spheroidizing is completed; (5), cutting off the inert gases, adding a slag accretion agent into the molten iron spheroidizing bag, and removing the protective slag; and (6), quickly pouring and preventing decaying spheroidisation. The method for improving the smelting quality of the molten ductile iron is simple in process and high in product quality.

Description

technical field [0001] The invention relates to a method for improving the smelting quality of molten iron. Background technique [0002] my country's foundry industry generally attaches great importance to molding technology, and often ignores the molten iron smelting that affects the quality of castings, so that my country's ductile iron parts are generally low-grade products, and the mechanical properties of ductile iron cannot reach the best international level. In addition to the design, it also has a lot to do with the smelting level of molten iron. [0003] When molten iron is melted and smelted, the foundry industry does not pay as much attention to the raw materials as the metallurgical industry. The metallurgical industry, especially the special steel smelting industry, has strict regulations on the raw materials that enter the furnace, such as the raw material baking system, the control of scale content, the precautions for the use of raw materials, etc. These are...

AI Technical Summary

Problems solved by technology

The metallurgical industry, especially the special steel smelting industry, has strict regulations on the raw materials that enter the furnace, such as the raw material baking system, the control of scale content, the precautions for the use of raw materials, etc. These are the prerequisites for ensuring high-quality molten steel, otherwise it will be given Smelting brings many difficulties, increases the cost of smelting, and even produces waste products

In the foundry industry, whether it is a cupola furnace or an intermediate frequency furnace, there are no strict requirements on the raw materials entering the furnace, and the inclusions and gas content in the molten iron are relatively high. Most of the castings are low-end products, and high-quality castings cannot be produced. , low value-added products

[0004] For ductile iron parts, a lot of rare earth oxides and sulfide inclusions will be produced during the spheroidizing process of molten iron. The specific gravity of these inclusions is not much different from that of molten iron, and it is difficult to remove them by floating. Into the castings, it seriously affects the mechanical properties of the castings, especially the low impact toughness