Electroslag Refining of CrNiMoWMnV Ultrahigh-Strength Steel

作     者：Mohammed Ali Mamdouh Eissa Hoda El Faramawy David Porter Jukka Kö mi M. F. El-Shahat Taha Mattar 

作者机构：Materials Engineering and Production Technology University of Oulu Oulu Finland Steel Technology Department Central Metallurgical Research and Development Institute Cairo Egypt Chemistry Department Ain Shams University Cairo Egypt 

出 版 物：《Journal of Minerals and Materials Characterization and Engineering》 (矿物质和材料特性和工程（英文）)

年 卷 期：2017年第5卷第6期

页      面：385-407页

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

主　　题：Ultrahigh-Strength Steel Electroslag Refining Alloying Elements Impurities Activity 

摘      要：Increasing demands for ultrahigh-strength steels in commercial as well as military applications have raised interest in finding alternatives to the high-cost high-alloyed steel and super-alloys currently used, e.g. the use of economic low-alloy compositions processed via low-cost air induction melting and electroslag refining (ESR). In this work the yield of alloying elements and the removal of the impurities nitrogen, sulphur and phosphorus as a result of electroslag refining (ESR) in a newly developed CrNiMoWMnV ultrahigh-strength steel (UHSS) have been studied in relation to their activities in the molten metal pool. Six experimental heats of CrNiMoWMnV UHSS with different chemical compositions were designed, melted in an induction furnace (IF) and refined using ESR. This was followed by hot forging of the ingots at 1100°C to 950°C. ESR using a CaF2-CaO-Al2O3 slag system led to a high yield in Cr, Ni, Mo, W, Mn and V, while the yield of Si is low. The desulphurization of all six UHSS grades was pronounced with most of the sulphur removed either to the slag or by gas reactions. The degree of dephosphorization was only 5% irrespective of the steel composition. On the other hand, denitrification (removal of nitrogen) was achieved. It ranged from 8% to 63% depending on the steel composition. The yield of the alloying elements and removal of impurities from the steel during ESR depends on the chemical and physical properties of the ESR slag and the activity of the elements in the molten state, taking into account elemental interactions.