Conversion to the Linz-Donawitz process ( or " basic oxygen " process ) of steel making from the open hearth process took place from the late 1960s onwards and was complete by the 1990s.
12.
For the steelmaking process itself, Roach and Salom selected the new Siemens-Martin open hearth process, which differed from the more well established Bessemer process by being slower and more easily controlled, allowing for a higher quality of finished product.
13.
Conversion to the Linz-Donawitz process ( LD ) of steel making from the open hearth process took place from the late 1960s onwards, with an intermediate oxygen utilising open hearth process known as the AJAX furnace operated in the interim conversion to LD operation was complete by the 1990s.
14.
The basic process, the Thomas-Gilchrist process, remained longer in use, especially in Continental Europe, where iron ores were of high phosphorus content and 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.
15.
Conversion to the Linz-Donawitz process ( LD ) of steel making from the open hearth process took place from the late 1960s onwards, with an intermediate oxygen utilising open hearth process known as the AJAX furnace operated in the interim conversion to LD operation was complete by the 1990s.
