pa1778data.pdf

U.S. STEEL DUQUESNE WORKS
HAER No. PA-115
(Page 11)
Complementing open hearth construction was the installation
of a full line of steam powered primary rolling and bar rolling
facilities. The installation of these facilities—which enabled
the works to produce bars in the shape of rounds, flats, and
squares—began with the construction of a 40" blooming mill, a
14" continuous billet mill, and two bar mills (10" and 13") as
part of the modernization effort that included the construction
of Open Hearth Number One.
A particularly significant feature of the new bar mills was
their ability to roll bars at lengths longer than the customary
limit of 50'. Until that time, the length of bars was limited
because of the uneven temperature of each billet which was being
rolled. Billets had been traditionally heated in batch furnaces
prior to rolling. When the billet reached rolling temperature,
it was removed from the furnace and run through the various roll
stands making up the bar mill. As the billet was being rolled,
however, the back end of the billet, which entered the rolls
last, cooled below the proper rolling temperature. This made it
impossible to reduce the entire billet to a uniform cross-
sectional diameter. As a result, a certain percentage of each
bar had to be scrapped at the end of the rolling process. In
order to keep the proportion of scrap to a minimum, billet
lengths were limited. The bar mills at Duquesne, however,
employed a continuous furnace whereby the back end of each billet
remained in the furnace until its front end had made its many
passes through the rolls, thus guaranteeing that the back end of
the billet remained at the proper rolling temperature when its
turn came to pass through the rolls. This made it possible to
use longer billets than before and thus allowed for an increase
in the length of bars. 11
36(January 1, 1903): 84-5; "The Duquesne Works of the Carnegie
Steel Company: The Open Hearth Plant and the Blooming and 14-Inch
Morgan Continuous Mills," The Iron Aae 71(January 1, 1903): 12-14;
Camp and Francis, eds., The Making, 200, 386-93; United States
Steel Corporation, The Making. Shaping, and Treating of Steelr
Sixth Edition, (Pittsburgh: 1951), 401; Duquesne Works, Steelmaking
Division, "Duquesne Works-Steel Production Conference, 1951," p.
41, Collection of USX Corporation; "Open Hearth Installation at
Duquesne Completed-Bessemer Converters Replaced," The Iron Trade
Review 45(August 5, 1909): 242; "Corporation's Electric Steel
Output," The Iron Age 97(June 1, 1916): 1329.
11 "The Open Hearth Plant and 40-Inch Blooming Mill of the
Carnegie Steel Co., at Duquesne, Pa.," 85-9; "The Duquesne Works of
the Carnegie Steel Company: The Open Hearth Plant and the Blooming
and 14-Inch Morgan Continuous Mills," 15-20; "The Duquesne Merchant
Bar Mills of the Carnegie Steel Company," The Iron Trade Review