Manufacturing method for prolonging service life of KR stirrer

Abstract

The invention discloses a manufacturing method for prolonging the service life of a KR stirrer, specifically comprising the steps of: selecting a steel core, removing impurities on the surface of the steel core, washing and cleaning the steel core, and airing; welding a group of riveting pieces with different heights ranging from 30mm to 80mm on the surface of the steel core; covering a refractory fiber material layer with the thickness of 0-50mm on the surface of the steel core, coating a castable layer with the thickness of 60-120mm on the refractory fiber material layer, and baking the entire device for 36-60h at the temperature of 80-100 DEG C; and continuously heating the baked device to ensure that the temperature reaches 320-350 DEG C, and maintaining the temperature for 8-16h. The method is simple and energy-saving, and the used materials are not molten at high temperature and can stop the heat from being transmitted to the steel core, therefore, not only is the expansion degree of the steel core alleviated, but also the extrusion stress generated due to the expansion of the steel core can be effectively buffered so that the quantity of the cracks generated after the KR stirrer is baked can be reduced to the minimum.

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