Editing Bessemer process (section)

===Patent===
[[File:William Kelly (inventor).jpg|thumb|upright|[[William Kelly (inventor)|William Kelly]] is credited with experimenting with a similar process before Bessemer's patent.]]
In the early to mid-1850s, the American inventor [[William Kelly (inventor)|William Kelly]] experimented with a method similar to the Bessemer process. Wagner
writes that Kelly may have been inspired by techniques introduced by Chinese ironworkers hired by Kelly in 1854.<ref name="wag"/> The claim that both Kelly and Bessemer invented the same process remains controversial.  When Bessemer's patent for the process was reported by ''[[Scientific American]]'', Kelly responded by writing a letter to the magazine. In the letter, Kelly states that he had previously experimented with the process and claimed that Bessemer knew of Kelly's discovery. He wrote that "I have reason to believe my discovery was known in England three or four years ago, as a number of English puddlers visited this place to see my new process. Several of them have since returned to England and may have spoken of my invention there."<ref name="wag"/> It is suggested Kelly's process was less developed and less successful than Bessemer's process.<ref>{{Cite web|url=https://engines.egr.uh.edu/episode/762|title=Kelly's Converter &#124; The Engines of Our Ingenuity|website=engines.egr.uh.edu}}</ref>

[[File:Schéma Bessemer métallurgie.svg|lang=en|left|thumb|upright|Principle of Bessemer process.]]

[[Sir Henry Bessemer]] described the origin of his invention in his [[autobiography]] written in 1890. During the outbreak of the [[Crimean War]], many English industrialists and inventors became interested in military technology. According to Bessemer, his invention was inspired by a conversation with [[Napoleon III]] in 1854 pertaining to the steel required for better artillery. Bessemer claimed that it "was the spark which kindled one of the greatest revolutions that the present century had to record, for during my solitary ride in a cab that night from Vincennes to Paris, I made up my mind to try what I could to improve the quality of iron in the manufacture of guns."<ref name="wag361">{{cite book |last=Wagner |first=Donald |title=Science and Civilisation in China: Vol. 5, Part 11: Ferrous Metallurgy |url=https://books.google.com/books?id=FAud8CE5stsC&pg=PA361 |year=2008 |publisher=Cambridge University Press |isbn=978-0-521-87566-0 |page=361}}</ref> At the time, steel was used to make only small items like cutlery and tools, but was too expensive for cannons. Starting in January 1855, he began working on a way to produce steel in the massive quantities required for [[artillery]] and by October he filed his first patent related to the Bessemer process. He patented the method a year later in 1856.<ref name="wag361"/>  William Kelly was awarded priority patent in 1857.<ref>{{Cite web |title=Kelly Pneumatic Iron Process |url=https://www.acs.org/education/whatischemistry/landmarks/kelly-iron.html |access-date=2023-11-03 |website=American Chemical Society |language=en}}</ref>

[[File:Henry Bessemer (1813-1898).jpg|thumb|upright|Henry Bessemer]]

Bessemer licensed the patent for his process to four [[ironmaster]]s,{{When|date=June 2021}} for a total of £27,000, but the licensees failed to produce the quality of steel he had promised—it was "rotten hot and rotten cold", according to his friend, [[William Clay (industrialist)|William Clay]]<ref name="Ericksonp141-142">{{cite book |first=Charlotte |last=Erickson |title=British industrialists: steel and hosiery 1850–1950 |year=1986 |orig-year=1959 |publisher=Cambridge University Press |pages=141–142 |author-link=Charlotte Erickson |isbn=0-566-05141-9}}</ref>—and he later bought them back for £32,500.<ref>{{Cite book |publisher=Offices of "Engineering" |last=Bessemer |first=Sir Henry |title=Sir Henry Bessemer, F.R.S. |url=https://archive.org/details/sirhenrybessemer00bess |year=1905}} p172.</ref> His plan had been to offer the licenses to one company in each of several geographic areas, at a royalty price per ton that included a lower rate on a proportion of their output in order to encourage production, but not so large a proportion that they might decide to reduce their selling prices. By this method he hoped to cause the new process to gain in standing and market share.<ref name="Ericksonp141-142"/>

He realised that the technical problem was due to impurities in the iron and concluded that the solution lay in knowing when to turn off the flow of air in his process so that the impurities were burned off but just the right amount of [[carbon]] remained. However, despite spending tens of thousands of pounds on experiments, he could not find the answer.<ref>{{harvnb|Anstis|1997|p=147}}.</ref> Certain grades of steel are sensitive to the 78% [[nitrogen]] which was part of the air blast passing through the steel.

The solution was first discovered by English metallurgist [[Robert Forester Mushet]], who had carried out thousands of experiments in the [[Forest of Dean]]. His method was to first burn off, as far as possible, ''all'' the impurities and carbon,<!-- SEE TALK PAGE – HISTORY REVERTS --> then reintroduce carbon and [[manganese]] by adding an exact amount of [[spiegeleisen]], an alloy of iron and manganese with trace amounts of carbon and [[silicon]]. This had the effect of improving the quality of the finished product, increasing its [[malleability]]—its ability to withstand rolling and forging at high temperatures and making it more suitable for a vast array of uses.<ref>{{DNB Cite|wstitle=Mushet, Robert Forester}}</ref><ref>{{harvnb|Anstis|1997|p=140}}.</ref> Mushet's patent ultimately lapsed due to Mushet's inability to pay the patent fees and was acquired by Bessemer. Bessemer earned over 5 million dollars{{clarify|date=July 2023}} in royalties from the patents.<ref>{{Cite book |publisher=Lewis Pub. Co. |last=Company |first=Lewis Publishing |title=A century and a half of Pittsburg and her people |date=1908}}</ref>

The first company to license the process was the Manchester firm of [[W & J Galloway & Sons|W & J Galloway]], and they did so before Bessemer announced it at Cheltenham in 1856. They are not included in his list of the four to whom he refunded the license fees. However, they subsequently rescinded their license in 1858 in return for the opportunity to invest in a partnership with Bessemer and others. This partnership began to manufacture steel in Sheffield from 1858, initially using imported charcoal pig iron from [[Sweden]]. This was the first commercial production.<ref name="Ericksonp141-142"/><ref>{{cite book |title=An Autobiography |last1=Bessemer |first1=Sir Henry |year=1905 |publisher=Engineering |location=London |url=https://archive.org/stream/sirhenrybessemer00bessuoft |pages=176, 180}}</ref>

A 20% share in the Bessemer patent was also purchased for use in Sweden and Norway by Swedish trader and Consul [[Göran Fredrik Göransson]] during a visit to London in 1857. During the first half of 1858, Göransson, together with a small group of engineers, experimented with the Bessemer process at Edsken near [[Hofors]], Sweden before he finally succeeded. Later in 1858 he again met with Henry Bessemer in London, managed to convince him of his success with the process, and negotiated the right to sell his steel in England. Production continued in Edsken, but it was far too small for the industrial-scale production needed. In 1862 Göransson built a new factory for his Högbo Iron and Steel Works company on the shore of Lake Storsjön, where the town of [[Sandviken]] was founded. The company was renamed Sandviken's Ironworks, continued to grow and eventually became [[Sandvik]] in the 1970s.<ref>{{Cite web|title=The Sandvik Journey : de första 150 åren - Ronald Fagerfjäll - inbunden (9789171261984) {{!}} Adlibris Bokhandel|url=https://www.adlibris.com/se/bok/the-sandvik-journey-de-forsta-150-aren-9789171261984|access-date=1 July 2020|website=www.adlibris.com}}</ref>