宝钢低夹杂物精炼.pdfVIP

PROGRESS OF PRODUCTION TECHNOLOGY OF CLEAN STEEL IN BAOSTEEL CUI Jian ZHENG Yiyu ZHU Lixin (Baoshan Iron and Steel Co., Ltd.) Abstraca: The progress in control technology of carbon, nitrogen, total oxygen, phosphorus, and sulphur as well as inclusions in steel is discussed at Baosteel. The purity obtained in IF steel and pipeline steel is introduced. Keywords: Clean steel; IF steel, Pipeline steel, Steelmaking 1 Preface The so-called clean steel generally is the steel in which the content of impurity elements, such as phosphorus, sulphur, total oxygen, nitrogen, hydrogen (including carbon sometimes) and inclusions, should be very low. The so-called impurity elements can change with different grades of steel. One element is a kind of harmful impurity in certain steel grade. It may be not harmful enough, even may be useful in another grade. In other words, the control elements are different for different performance demands of steel. For IF steel, the content of carbon, nitrogen, total oxygen and inclusions in steel should be as low as possible in order to gain good stretchability, high r value, perfect surface quality and reduce the amount of the micro-alloy elements. The high quality pipeline steel should have ultra low sulphur, low phosphorus, low nitrogen, low total oxygen content and a certain ratio of Ca/S. Since the middle period of 1990’s, Baosteel has endeavored to develop the melting technology of clean steel. The research work concentrates on the development of relatively individual technologies and mass production of high cleanliness steel (IF steel, pipeline steel etc.). This paper presents the progress of production technologies of clean steel in Baosteel. 2 Progress of