ON THE PRESENT POSITION OF ELECTRIC STEEL MELTING. 261 



The Present Position of Electric Steel Melting. 

 Report by Professor Andrew McWilliam, A.R.S.M., M.Met. 



[Ordered by the General Committee to be printed in exU «so.] 



The melting of steel by means of electricity has passed the merely 

 experimental stage and become one of the commercial processes by 

 means of which steel is manufactured for the market. It is not correct 

 to say that it has emerged from the experimental stage, as not only 

 this process of steel-making but most other processes are being con- 

 tinually experimented with and the results compared with one another 

 by up-to-date and vigorous firms, not only for the new conditions that 

 are always arising but also for old and well-tried conditions. 



A new demand arises or repeat orders come in, and the manufacturer 

 must ask himself what kind of steel will best suit the purpose at the 

 present time. Will Bessemer or Open-hearth steel be most suitable 

 to satisfy the demand, price, quality, and all other matters considered 

 and must it be acid steel or will basic do, or is it necessary or desirable 

 to use crucible steel or perhaps this new electric steel, to maintain or 

 increase his profit or his reputation for certain goods ? These are prob- 

 lems of daily occurrence, and although the difficulties of the manu- 

 facture of electric steel by various processes have been fairly well over- 

 come, so far as making it to specification of chemical composition and 

 mechanical tests is concerned, it is in connection with such questions 

 as are indicated in the previous sentence that it is still in the earlier 

 experimental stage. All other processes, however, are more or less 

 under such trials until they become extinct. The point need not be 

 laboured, for many examples will come to the mind at once, such as 

 the comparative merits for various purposes of Swedish-Lancashire and 

 Walloon iron; of mild steel and wrought iron; of acid and basic steel, 

 and so on. The general impression gathered from much conversation 

 with users is that the arc furnace product from slightly impure 

 materials, purified to Swedish standard, just about takes its place by 

 Swedish Open-hearth and Bessemer steels and that the induction 

 furnace product skilfully made from pure materials equals anything 

 but the very highest qualities of crucible steels. These are very general 

 statements but they represent the writer's present more or less intuitive 

 opinions, and only time can determine whether they are correct, for 

 the fact that steels are of certain chemical compositions and give cer- 

 tain mechanical tests is not a final judgment, but the quality and 

 length of service given in actual use. The special feature of the 

 H6roult and Rochling-Rodenhauser types is that with an oxidising 

 purification phosphorus can be eliminated to almost any extent that 

 will pay, and after removing the slag, and forming another, by a 

 reducing purification sulphur can similarly be removed. 



The Kjellin induction furnace acts as a melter of materials much 

 after the manner of the crucible, and has one advantage over the cru- 

 cible in that there is no absorption of sulphur during melting. Recent 

 experiments with covering slags specially calculated by the writer to 



