Online
Help and SOP Integration
John W. Stanchin Sr.,
supervisor and senior technology engineer — steelmaking
and continuous casting, WCI Steel Inc., Warren, Ohio (jwstanchin@wcisteel.com)
When
an event on the shop floor triggers an alarm, operators need
timely access to standard operating procedures. WCI Steel
uses an online system at its continuous caster mold that provides
immediate alarm descriptions and procedures, thereby decreasing
the likelihood of extended downtime.
Fast
Commissioning of Modernized Loopers Supported by a “Hardware
in the Loop” Test
Matthias Tuschhoff
(left), deputy general manager — process measuring technology,
and Olaf N. Jepsen (right), SMS Demag Aktiengesellschaft,
Düsseldorf, Germany (matthias.tuschhoff@sms-demag.de);
and Matthew M. Morris, North Star BlueScope Steel LLC, Delta,
Ohio
In
a modernization of loopers in a hot strip mill, the control
system was tested using a simulation model prior to commissioning.
The hardware concept and the main features of the simulation
model are presented, and test results are compared with real
plant behavior.
Productivity
Improvements in Steelmaking via Sensor-based Steelmaking Process
Control
Randall P. Stone (pictured),
senior products applications manager, Heraeus Electro-Nite Co.,
Langhorne, Pa. (rstone@electro-nite.com); Ray M. Figas Jr.,
formerly of Heraeus Electro-Nite Co. (ray.figas@sglcarbon.com);
and Robert V. Branion, principal consultant, Branion Associates
Inc., Valparaiso, Ind. (r.remus@verizon.net)
Technology
exists for rapid, sensor-based, real-time analysis of sulfur,
silicon, slag and steel oxygen activity. From these data,
the desired quality and productivity goals can be achieved.
Implementation of new process control sensors, along with
anticipated benefits, is discussed.
Development and Implementation of a Setup Model in
the SIDOR
Temper Mills
Luis Lozano (top left),
models group chief, Juan Colmenares (top right), automation
engineer, Olga Prado (bottom left), project coordinator, Jose
Lara (bottom center), automation engineer, and Luis Quiroz
(bottom right), automation engineer, SIDOR C.A., Bolívar,
Venezuela (sirllo@sidor.com, sirjuc@sidor.com, sirhol@sidor.com,
sirljw@sidor.com, sirqul@sidor.com)
Through
the implementation of a physical-mathematical setup model
at SIDOR’s temper mills, the amount of reprocessed material
decreased, there were fewer cylinder changes, and both productivity
and product range increased.
Control System Upgrade for Nucor-Yamato Steel Beam Mill
No. 1
Joseph S. Klak Jr., senior
project engineer, Rockwell Automation, Drives Systems Business,
Mayfield Heights, Ohio (jsklak@ra.rockwell.com)
With initial
production beginning in July 1988, the control system for
Nucor-Yamato Steel’s No. 1 beam mill was aging. This
article details the successful replacement of the programmable
controllers with new equipment, the upgrade of the DC drives
with new digital regulators and the replacement of the CSI
inverters with PWM drives.
Thermodynamic
Analysis on the Formation and Chemical Development of Nonmetallic
Inclusions in Ladle Treatment of Tool Steels
Kristina Beskow, Ph.D.
student, and Du Sichen, professor, Department of Materials
Science and Engineering, Royal Institute of Technology, Stockholm,
Sweden (kristina.beskow@uddeholmtechnology.se, du@mse.kth.se);
and Nobuo Sano, professor, Nippon Steel Corp., Japan (sano@re.nsc.co.jp)
A thermodynamic analysis was carried out to reveal the mechanisms
of the formation and chemical development of nonmetallic inclusions
in ladle treatment of tool steels. In parallel, an industrial
investigation was conducted at Uddeholm Tooling AB, Hagfors,
Sweden. The inclusions found in the steel samples taken at
different stages of ladle treatment were analyzed and identified
under a scanning electron microscope with an EDS x-ray analyzer.
Six types of inclusions were found. The types of inclusions
were found to vary with the stage of ladle treatment. Thermodynamic
analysis could successfully explain the formation and the
chemical development of the inclusions throughout the process.
Three types of inclusions were found in the liquid steel before
deoxidation, namely, type A (liquid inclusions with high SiO2
concentration), type B (spinel) and type C (a combination
of A and B). Thermo¬ dynamic analysis indicated that these
types of inclusions could be generated by the reaction between
EAF slag and the ladle glaze during the filling of the ladle.
The addition of aluminum would form the alumina inclusions
(type E), which agglomerated and floated up quickly. The spinel
inclusions would not be stable at low oxygen potentials. The
inclusions of this type would react with the liquid metal,
forming inclusions of type F (spinel in the center surrounded
by an oxide solution containing Al2O3, CaO and MgO). Furthermore,
reaction between the liquid metal and inclusions of type F
would result in the inclusions of type G, an oxide solution
consisting mostly of Al2O3 and CaO with small amounts of MgO
and SiO2. |
