Editing Bessemer process (section)

==Obsolescence==
As early as 1895 in the UK it was being noted that the heyday of the Bessemer process was over and that the [[Open hearth furnace|open hearth]] method predominated. The ''Iron and Coal Trades Review'' said that it was "in a semi-moribund condition. Year after year, it has not only ceased to make progress, but it has absolutely declined." It has been suggested, both at that time and more recently, that the cause of this was the lack of trained personnel and investment in technology rather than anything intrinsic to the process itself.<ref>{{cite book |title=The development of British industry and foreign competition, 1875–1914; studies in industrial enterprise |editor=Aldcroft, Derek H. |chapter=Iron and steel manufactures |author=Payne, P. L. |pages=92–94, 97 |publisher=George Allen & Unwin |location=London |year=1968 |oclc=224674}}</ref> For example, one of the major causes of the decline of the giant ironmaking company [[Bolckow Vaughan]] of Middlesbrough was its failure to upgrade its technology.<ref>Abe, E. The Technological Strategy of a Leading Iron and Steel Firm: Bolckow Vaughan Co. Ltd: Late Victorian Industrialists Did Fail. Business History, 1996, Vol. 38, No. 1, pages 45–76.</ref> The basic process, the Thomas-Gilchrist process, remained in use longer, especially in Continental Europe, where iron ores were of high phosphorus content<ref>{{cite web |url=http://www.tms.org/pubs/journals/JOM/0307/Dean-0307.html |title=Rail that Survived Demolition by "Lawrence of Arabia": An Analysis |website=www.tms.org |access-date=23 February 2018 |archive-url=https://web.archive.org/web/20171122084235/http://www.tms.org/pubs/journals/JOM/0307/Dean-0307.html |archive-date=22 November 2017 |url-status=dead }}</ref> and the open-hearth process was not able to remove all phosphorus; almost all inexpensive construction steel in Germany was produced with this method in the 1950s and 1960s.<ref>{{Cite web |url=http://www.economypoint.org/t/thomas-process.html |title=Thomas process / Metallurgy - Economy-point.org |access-date=24 February 2012 |archive-url=https://web.archive.org/web/20130203062841/http://economypoint.org/t/thomas-process.html |archive-date=3 February 2013 |url-status=dead }}</ref> It was eventually superseded by [[basic oxygen steelmaking]].

In the U.S., commercial steel production using this method stopped in 1968. It was replaced by processes such as the [[Basic oxygen steelmaking|basic oxygen (Linz–Donawitz) process]], which offered better control of final chemistry. The Bessemer process was so fast (10–20 minutes for a heat) that it allowed little time for chemical analysis or adjustment of the alloying elements in the steel. Bessemer converters did not remove phosphorus efficiently from the molten steel; as low-phosphorus ores became more expensive, conversion costs increased. The process permitted only limited amount of [[scrap]] steel to be charged, further increasing costs, especially when scrap was inexpensive. Use of [[electric arc furnace]] technology competed favourably with the Bessemer process resulting in its obsolescence.

Basic oxygen steelmaking is essentially an improved version of the Bessemer process (decarburization by blowing oxygen as gas into the heat rather than burning the excess carbon away by adding oxygen carrying substances into the heat). The advantages of pure oxygen blast over air blast were known to Henry Bessemer,{{Citation needed|date = January 2016}} but 19th-century technology was not advanced enough to allow for the production of the large quantities of pure oxygen necessary to make it economical.