English to Italian Tech/Engineering Metallurgy / Casting

Then, in the year 1907, a Swede named Oscar Kjellberg made a further improvement by coating the metal electrodes with a ** a slag-forming flux ** consisting mainly of chalk and a binding agent, but it was not until the year 1911, when Mr. Arthur P. Strohmenger patented the use of an electrode covered with blue asbestos yarn, that electric fusion welding was seriously considered for use in iron and steel constructional work.