Production method capable of prolonging service life of KR (Krypton) stirrer

Abstract

The invention discloses a production method capable of prolonging the service life of a KR (Krypton) stirrer. The production method includes steps of manufacturing a stirring blade with a steel core into a composite body with metal and pouring materials, arranging metal steel plates on two sides of the stirring blade with the steel core and filling the pouring materials in the middle of the stirring blade with the steel core; removing impurities on the surface of the steel core, washing the steel core, drying the steel core and welding a group of anchoring parts with the size ranging from 30mm to 80mm on the surface of the steel core; fixing a mold well on the periphery of the steel core, pouring the pouring materials in the mold, then placing the mold poured with the pouring materials at room temperature until the pouring materials are hardened, and maintaining the pouring materials for 48 hours to 72 hours after the mold is removed; baking the integral KR stirrer for 36 hours to 60 hours at the temperature ranging from 100 DEG C to 150 DEG C after maintenance is completed; and continuing heating the baked KR stirrer, leading the temperature to reach a range between 320 DEG C and 350 DEG C, and maintaining the temperature for 8 hours to 16 hours. By the aid of the production method, expansion degree of the steel core is reduced, extrusion stress due to expansion of the steel core can be effectively buffered, and accordingly the amount of cracks after the KR stirrer is baked can be reduced to the greatest extent.

Description

technical field [0001] The invention belongs to the field of metal smelting, and in particular relates to a preparation method for improving the service life of a KR agitator. Background technique [0002] The KR stirring desulfurization method is a desulfurization technology outside the molten iron furnace that Japan's Nippon Steel Wentian Iron Works began to study in 1963 and was applied to industrial production in 1965. The desulfurization method has the characteristics of high desulfurization efficiency, less desulfurization agent consumption, short operation time, low metal consumption and low refractory material consumption. In the 1970s, my country's Wuhan Iron and Steel introduced KR stirring desulfurization technology from Japan's Nippon Steel, and other domestic companies also successively introduced or designed and prepared KR stirring desulfurization production lines, which opened up a new pattern for the development of my country's molten iron desulfurization te...

AI Technical Summary

Problems solved by technology

In the preparation process of KR agitator, the most difficult thing to deal with is how to reduce the extrusion internal stress caused by the difference in thermal expansion between the two materials of the agitator complex (castable and steel core) during the baking process; During the baking process, due to the extrusion force of the steel core, cracks of different thicknesses appear inside and on the surface of the castable. During service, molten iron penetrates into the material interface through the cracks and causes large pieces of the castable to fall off, causing the KR mixer to be scrapped in advance.

[0004] In order to improve this phenomenon, some measures have been taken, such as wrapping one or several layers of plastic materials on the surface of the steel core, and further applying a layer of buffer coating on the surface. These measures have played a certain role in reducing the stress difference, but at high temperatures Under these conditions, the cushioning effect of these materials is limited due to melt flow