McLouth Steel

McLouth Steel Corporation
Industry Steel
Fate Bankruptcy
Successor Detroit Steel Company
Founded 1934
Defunct 1996
Headquarters Detroit, MI 1934-1981, Trenton, MI1982-1996
Products Low carbon and stainless strip steel

McLouth Steel is a former integrated steel company. The company was once the ninth largest steelmaker in the country, and had three locations. The first plant was in Detroit, Michigan, the second (and significantly larger) in Trenton, Michigan, and the third, a cold mill, in Gibraltar, Michigan. The Detroit plant is currently owned by Jones & Laughlin Steel Company. The Trenton facility is owned by Detroit Steel Company, and around half the site remains, including the rolling mill. The Gibraltar cold mill is owned by Ferrolux, and has been restarted.

Detroit Complex

This plant was built by Donald B. McLouth as a small conversion mill on Livernois Avenue in Detroit, MI. The plant was revamped to produce only stainless steel in its later years and was bought by Jones and Laughlin Steel Company in 1981.

The Detroit mill initially consisted of a small reversing hot rolling strip mill with a slab heating furnace. The original hot strip mill was known as the "Coffee Grinder" from the sounds the mill would make. In 1938, the company brought online a single 4-high reversing cold reducing mill with ancillary facilities (annealing and finishing). Throughout the next few years, modifications were made to the equipment and eventually, the company had the capacity to roll 108,000 net tons per year of hot rolled products and 60,000 net tons of cold rolled steel products.

In 1947 McLouth Steel began rolling stainless steel. Two single stand reversing cold reducing mills were installed with the related supplementary equipment. In 1954, $6,000,000 of the $100,000,000 expansion plan for the new Trenton plant was used to install two 4-high reversing cold rolling mills. With this new addition to the Detroit plant, the stainless steel production was increased to 52,000 net tons per year.

The Detroit plant is a finishing facility for sheet and strip products only. Principal operating units are two 50-inch (1,300 mm)., 4-high cold reduction mills, a cold anneal and pickle line, a temper mill, two slitting lines(36in. and 24in.), and a coil polisher. The two 50in. reduction mills, are essentially identical. Both were installed in 1953 by United and combined, they both have an annual capacity of 120,000 tons. The cold anneal and pickle line was installed in 1975 by Production Machinery. The line consists of an entry end washing section to remove rolling oils, an open air annealing furnace where the strip is heated above 1,900 °F (1,040 °C) and three acid pickling tanks followed by rinsing and drying units. Paper is interleaved between the coil wraps at the exit take up reel to avoid surface abrasion.

Coil product was usually shipped from the Detroit plant via truck.


Trenton Complex

A photograph showing the majority of the Trenton, MI plant.

In 1948, McLouth Steel started its $100 million expansion program by purchasing riverfront property in Trenton, MI. Construction on the first major construction program was started soon afterward. The site was laid out and four sixty ton electric arc furnaces were installed. Soaking pits, a blooming mill, a Steckel mill, a down-coiler and finishing equipment were installed. The first ingots were poured in 1949, and McLouth was soon established as a growing factor in the marketplace.

A few years later, in 1954, the Trenton Plant was dedicated and McLouth Steel became able to produce iron as an integrated steel mill. Number One blast furnace was constructed with a capacity of 1250 tons a day. The three original 60 ton basic oxygen furnace (BOF) vessels were installed and McLouth became the first plant in North America to make steel via the basic oxygen process. Adding to the melt shop were two 200 ton electric arc furnaces. The reversing Steckel mill was replaced by a six stand continuous 60-inch (1,500 mm) hot strip rolling mill and a roughing stand was added to compliment the blooming mill. More soaking pits were installed as well as a plant to supply the BOP with oxygen. Two pickle lines were also added along with the slitters.

1958 saw another major expansion of the plant. A new blast furnace was constructed (Number 2), two 110 ton BOP vessels, and the related support equipment for the BOP and blast furnaces also had their capacity increased. Gas cleaning systems were installed for the melt shop as well. Two Rust slab reheat furnaces were installed to handle stainless steel, as well as the massive grinder and slab unpilers. The grinders, unpilers, and the pusher/bumper units for the two furnaces were supplied by Composite Forgings, Inc.

Between 1960 and 1964, one more 110 ton BOP vessel was added, bringing the 110 ton vessel count to three. McLouth also became the first company to use computer controls on a hot strip mill on November 1, 1962. Significantly, the first "straight stick" slab caster was installed during this period. It was the first in the United States.

Profitable operations as well as market demand prompted a major commitment to build a Continuous Casting department in 1967 with the announcement of four curved mold continuous casting strands and six lines of three induction slab reheaters. Two additional 110 ton BOP vessels were also added to replace old and obsolete equipment (the 60 ton vessels). With these improvements to McLouth's steel making process, McLouth became the first steel mill to eventually produce 100% of its product by the continuous casting process, which added significantly to the efficiency of the operations and improved the quality of the finished product.

The plant was sold in 1996 to Detroit Steel Company. After several failed start-up attempts, the Trenton complex remains idle. The plant's electric distribution infrastructure was removed in the summer of 2009. Today, the land operates as a storage and transloading space for Trenton Marine Terminals.

Gibraltar Complex

In 1954 McLouth announced the construction of a cold rolling facility in Gibraltar, Michigan, close to the Trenton Plant. This facility has a four stand continuous cold rolling strip mill, annealing furnaces, two skin pass finishing mills and other ancillary equipment for further processing of cold rolled steel coils.

The property the company acquired that was once owned by the Gibraltar Steel Corporation. The total area was around 900 acres (3.6 km2) of land along the river bordering Trenton. McLouth failed to get the proper financing to construct another integrated mill, so plans were drawn up for a stand-alone cold rolling mill. Original plans called for five additional blast furnaces, but that was based upon the completion of the All American Channel. Without the channel, ore and coal haulers could not bring in the required raw materials.

There was a major fire that destroyed most of the pickling tower in 1970.

The plant was operated under Detroit Cold Rolling (a subsidiary of Detroit Steel) from 1996 (after the McLouth sale) until it was later sold to Steel Rolling Holdings in 2006. The plant was restarted by SRH, and was later purchased by Ferrolux. Ferrolux has since invested heavily into the Gibraltar facility, also adding jobs.

One of three original BOP furnaces from the plant

Trenton Plant Assets

Iron Making

Number 1 and number 2 furnaces were built in 1954 and 1958 respectively, by the Arthur McKee company. The hearth diameter was 28' 6" with a working volume of 56,676 cubic ft.
Phased out in 1969. Only the first floor of original building remains. Very inefficient - it produced low grade ore from wastes from the blast furnaces.
Built by Dravo Corp. Two cranes in 1954, with the last in 1958. 12 net tons each.

Steelmaking

Oxygen Process shop

Three 60 ton vessels added in 1954.
First successful basic oxygen shop in the United States. This shop was dismantled in 1968 as a result of the high operating costs compared to OP 2.
Five oxygen process vessels
Two 110 ton vessels added in 1958, one more 110 ton vessel added in 1960, two more added in 1968. All five were built by Pennsylvania Engineering Company (PECOR).
The reason that relatively small 110 ton vessels were used, was due to the low ceilings in the existing building.

Melt Shop

Four 60 ton electric arc furnaces installed in 1948 as the first expansion project.
Two 200 ton electric arc furnaces installed in 1954 to replace the four original furnaces.

A.O.D shop

Installed in 1977. 100 Net ton heat size. Three argon oxygen decarburization vessels were installed by PECOR.
Only a 39 of heats produced by this process. Average time per heat was 2 hours and 15 minutes. Later dismantled and turned into the ladle metallurgy station.

The entire steelmaking building, with the exception of the lime storage building, was demolished in 2005. The lime storage building was brought down with explosives on 18 April 2010.

Continuous Casting

Pilot plant

The first straight stick slab casting machine in America was installed in 1963. The machine was located south of OP 1. Schloemann was the main equipment vendor. Dismantled in 1968.

Concast department

Four low profile curved molds with progressive straightening.
Three molds cast 12" thick while the other casts 9.5". All molds could adjust the width from 36" to 57". Typical casting speed was 34-46 inches per minute for a 12" slab, and 48-55 IPM for a 9.5" slab. Maximum 120 inches per minute.

Main building was demolished in 2006. The four underground strands are still intact, however they are flooded. Cutting tables, control rooms, and service cranes have severe flood damage.

Hot Strip Mill

Furnaces

Soaking pits

5 two hole batteries. Natural gas fired. Built by Amsler Morton and the Rust Furnace Company in 1948.

Reheat Furnaces

Two conventional three zone, natural gas furnaces that were primarily used to reheat stainless and carbon slabs prior to the caster installation. 125 Net tons per hour each.
First furnace was installed in 1954. Second in 1958. Both were built by the Rust Furnace Company of Pittsburgh, PA.

Eighteen induction slab heating furnaces

Three lines of three heaters were installed in 1968, the last three lines were installed in 1969. Heaters were provided by Ajax Magnethermic and the slab handling equipment by United Engineering and foundry.
Maximum rated capacity was 645 tons per hour.

Walking beam furnace

Built in 1985. Natural gas fired. 350 tons per hour. 1 hour heating time per slab.

Rolling

Blooming Mill

Two high 41" diameter x 92" rolls. Built by Continental in 1948. Accepted ingots up to 24" x 44" and slabs up to 57" by 12" thick. Twin 3000 horsepower motors.

Roughing Mill

Two high 43" dia. x 59.75" rolls. Built by Mesta in 1954. Twin 2500 horsepower motors.

Six Stand 60-inch (1,500 mm) Rolling mill

Four high mill stand, 25.75" x 64" work rolls and 53.75" x 60" back up rolls. Built by Mesta in 1954. Five 5000 HP motors and one 3500 HP motor. Maximum entering plate is 1.25" thick. Minimum exiting strip is .071"

Two down-coilers

Installed in 1965 by Mesta. Produced a 78" maximum opening coil.

Finish Departments

Pickle Line

Built by Mesta in 1954. Used sulfuric acid. The line accepted coils up to 60" at a rate of 90 net tons an hour. The line is 553 feet long.

Slitters

Number 1 slitter
This line had a maximum coil width of 44" and 70" in diameter. Slitting width was 2.001" minimum, 42.5" maximum. Built by Wean in 1948.
Number 2 slitter
60" maximum coil width 72" diameter. 5" minimum, 55" maximum slitting width. Built in 1948 by Wean.
Number 3 slitter
60" maximum coil width 72" diameter. 2.001" minimum, 56" maximum slitting width. Built by Wean in 1948.
Number 4 slitter
60" maximum width. 5" minimum, 56" maximum slitting width. 45,000 PSI shear. Built by Wean in 1954.
Number 5 slitter
20" minimum, 60" maximum entry coil. 50,000 PSI shear. 9" minimum slit width. Built by Production Machinery in 1964.

Pickle line and #5 slitter remains.

Gibraltar cold mill assets

Pickle Line

Pickle liquor

Hydrochloric Acid, 10,000 gallon capacity.
175°F, 10-12% HCL, 12-15% FeCL

Tower

Vertical two pass line. First of its kind in North America. 90 tons per hour maximum capacity. Built by Dravo and Mesta in 1963.

Tandem Mill

Mill Stands

60" 4-high, 4-stand continuous.
Maximum 3300 feet per minute. Average speed at 2100 FPM.

Rolls

Back-up roll 53 x 60"
Work roll 22 x 60"
Width range was 26" to 52" wide.

Reduction Capability

1 stand-30%, 2 stand-25%, 3 stand-20%, 4 stand-10%

Annealing

60" Lee Wilson Bases

122 (60 in 1954; 15 in 1955; 47 in 1961)
48 Furnaces of the radiant tube type.
Charge size was 60" x 162" high.

80" Swindell Bases

90 (36 in 1968; 27 in 1971; 27 in 1974)
38 Furnaces of the direct fire type.
Charge size was 80" x 162" high.

Both furnaces used natural gas fuel.

Skin Mill

Two 2-high skin pass mills.

Built by Continental in 1954. 1500 Horsepower motors. Maximum speed of 3200 FPM, average of 2800.

Roll sizes

32" x 60"

Finishing Departments

Customer Service Line

Built by Wean in 1967. Line speed is 150' to 1000 feet per minute.
60 inch maximum width, 20 inch minimum.

Flying Shear Line

Two lines installed by Mesta in 1954. 800 FPM line speed.
Cut lengths are 48 inches to 144 inches.

Coil Slitting Line

Two lines built by Seco in 1954. 400 FPM line speed.

First Online Computer Control

Online computer control of steel making processes became a reality with the first use of computers on a hot strip mill in 1962. McLouth Steel used a General Electric 312 computer for gauge control on the finishing train of a semi-continuous mill. The aim was to set up the initial roll gap and then establish correct gauge as soon as the head end of the strip emerged onto the runout table. The finishing train started running under continuous computer control on November 1, 1962.

"Probably the most exciting application of the GE 312 was to the hot strip mill of McLouth Steel Co. in Michigan. It was a difficult design inasmuch as each step in the process had to be varied on the basis of the measured values of the previous step. This required continuous high speed feedback to set the six different hot stands with absolute accuracy and reliability being essential; an error at one point could be magnified at the next, causing an entire process to go out of control. Fortunately, the GE 312 met the challenge." H. Oldfield, General Manager of the GE Computer Department.

The Solid State circuitry of a GE 312 computer was composed of 2500 diodes, 2500 transistors, and 12,000 resistors, but no magnetic core memory. There were 20 binary digits per word or per instruction. All arithmetic was fixed point. Numbers were 19 bits plus the associated positive or negative sign, not a very big number range when expressed in decimal form, just -524,287 to +524,287. The GE 312 was designed by A. Spielberg of the GE Computer Department that was newly formed in 1957.[1]

First Continuous Caster

McLouth Steel was the first plant in North America to cast 100% of its steel by the continuous caster method.

In May 1962, McLouth personnel visited the Dillingen Steel Works in Germany, where continuously cast slabs larger than 100 square inches were first cast. Some sixteen months later McLouth was operating a "straight stick" casting machine.

Pilot Plant

In 1963, a full size single strand, vertical casting machine was added to the original Oxygen Process Shop. The machine was operated for five years, helping to pioneer techniques that would be useful when the larger four strand shop was constructed in 1968. The pilot shop was operated mostly during the day, while the afternoon and midnight shifts would repair, modify, or tune the machine.

Initial slab sizes were 8" x 36", afterwards they began to cast bigger slabs by about 10" increments up to 10" x 52". There was a noted improvement in quality, as with the ability to cast using larger molds. The pilot plant was limited to about 50 "heats" (ladles of molten steel), from the original OP shop. Over the course of operation, the pilot plant cast a little over 300,000 tons of steel.

The five year run of the plant produced the opportunity to help develop both the equipment and casting techniques. Extensive work was performed on the design of the molds and the casting speed relative to the slab quality.

Casting Plant Description

Four single-strand curved mold casting machines cast around 3000 tons per day. Only two casting machines will normally cast at one time and many people questioned the need for four units. McLouth felt that the third caster is there for coordination reasons while the fourth is a reserve for maintenance shutdowns. Ladles are moved by overhead bridge cranes to the casting machines which can handle two at a time.

The record slab length for the plant was between May 9–11, 1972. The slab was 44" wide and 9,972 feet (3,039 m) long, total weight was around 8,500 tons from 75 ladles. Strand two was used. [2]

First Use of Slab Induction Heating

McLouth Steel's decision to cast unusually thick slabs (12 inch) led them to reheat the slabs inductively. The whole setup was difficult to undertake, as well as uneconomical to use. The giant heaters resembled upside-down toasters, and made a loud buzzing sound when in operation.

The nature of the induction heating process is such that heat input to the slab is not restricted to the surface, but actually penetrates into the slab. The depth of penetration is determined by the frequency of the electrical power supply and the metallurgical makeup of the steel.

Although induction heating was well established as an effective and economical process fulfilling many types of heating requirements, it had never been seriously considered for heating anything like the 12" thick by 60" wide by 26' long, 30 ton slabs McLouth wanted to produce. The fact that they wanted over 600 tons of steel heated per hour did nothing to help the situation.

Several induction heating companies were contacted to determine if they would be interested in a project of this magnitude. Just one company expressed interest. Ajax Magnethermic from Warren, Ohio. Ajax informed McLouth that they had a new coil design which would be capable of doing the job. After discussions, McLouth entered into a shared cost, joint development venture with the company to design, build, and test a prototype coil system.

Early in 1965, several small 12" thick slabs of rimmed steel were repetitively heated in a prototype 1,000 kW rectangular coil. The tests proved that cold 12" thick slabs could be heated to rolling temperature in less than one hour.

The next year, McLouth ordered 21 heaters (including three spares) as part of a $105 million program expected to be completed by the summer of 1968. The program expanded the hot metal facilities with a four strand caster and the new induction heaters. Production capacity at the plant was raised from 1,800,000 tons a year to 2,400,000.

A full size computer system was installed to automatically switch heaters on or off as required to rebalance the phase loading and to remove the threat of a 120 KV line outage. Detroit Edison permitted McLouth a maximum phase imbalance of 43 MW. The computer shut off heaters if a limit was reached and provided printouts of hourly demands, alarms, engineering logs, as well as maintenance logs.

Overall, the system was a novel idea, but really only worked on paper. Auto transformer failures were frequent, as were bus connection failures. When all 18 heaters were running at full capacity, McLouth Steel was Michigan's second largest consumer of electricity (first was the city of Detroit). The environmental impact was very low due to a closed water cooling system and heaters being shut off during non-operating hours. [3]

References

  1. ↑ Ironmaking and Steelmaking 2004 VOL.31 No 6.
  2. ↑ McManus, George J. Slab Casting Pays Off, IronAge, November 30, 1972
  3. ↑ Induction Heating of Slabs at McLouth Steel. Ronald H. Craig - Chief Electrical Engineer

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