作者：KEIICHIRO AKAMINE;ISAO SASAKA;ARITO MIZOBE;

作者单位：Technical Center, Krosaki Harima Corp. 1-1 Higashihama-machi, Nishiyahata-ku, Kitakyusyu-shi 806-8586

刊名：Journal of the Technical Association of Refractories

ISSN：0285-0028

出版年：2004-01-05

卷：24

期：2

起页：135

止页：140

分类号：TQ175

语种：英文

关键词：

内容简介

Slide gate nozzles plates (SN plates), in general, are required to have high spalling resistance, high corrosion resistance, and high hot strength. A widely used material group to meet these requirements is Al_2O_3-ZrO_2-(SiO_2)-C. Many refractories of this group are fired at temperatures above 1000 deg C to form bonds including carbon bond formed when phenol resin added as a binder is carbonized, and metal bond and carbide bond produced when metals such as silicon, aluminum, and their alloys undergo reaction sintering~(1,2)) Besides those burnt refractories, unburnt refractories are also used for SN plates. Their formulas contain aluminum, and they are called "unburnt" because they are fired at temperatures below 500 deg C. Compared to burnt products, unburnt SN plates are characterized by higher corrosion resistance and hot strength~3), but they suffer from lower cold strength, volume instability at high temperatures, and lower spalling resistance once subjected to heat load. These problems put a limit on the size of unburnt SN plates. Semi-burnt SN plates were developed to overcome such problems of unburnt refractories. Their formulas contain aluminum, and they are fired in a temperature range of 500~1000 deg C. Compared to unburnt plates, they have higher cold strength and higher oxidation resistance, while maintaining high corrosion resistance and high hot strength characteristic of unburnt SN plates. When used for high oxygen steel, large semi-burnt SN plates proved more durable than burnt plates~4). When large plates with a large bore were used for ordinary steel, however, peculiar cracks were found around the nozzle bore and the bore had eroded and enlarged more than those of burnt plates. We investigated the cause of this wear, and based on the findings, took measures to improve the semi-burnt SN plate. This paper reports the results of our investigation and improvement.