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| VOLUME 24
| NUMBER 3 | THIRD
QUARTER 2003 |
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| New Allegheny Technologies President
and CEO Announced |
Allegheny
Technologies is pleased to announce that Mr. L. Patrick
(Pat) Hassey became President and Chief Executive Officer
of the Corporation on October 1, 2003. He replaces Mr.
James Murdy.
Mr. Hassey has 35 years of broad international experience
in metals manufacturing, engineered products, marketing
and sales. He was Executive Vice-President and a member
of the corporate executive committee at Alcoa, Inc., at
the time of his early retirement in February 2003. Prior
to becoming President and CEO of Allegheny Technologies,
Mr. Hassey had been working as an outside management consultant
to ATI executive management.
Mr. Hassey is a graduate of California State University
at Long Beach and attended the University of Southern
California MBA Program.
For more information about Allegheny Technologies, including
the latest corporate news releases, visit www.allghenytechnologies.com.
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QUESTION & ANSWER |
| Welding Zirconium to Titanium |
| By: Derrill Holmes, Rick Sutherlin
and Randy Scheel — ATI Wah Chang |
This issue’s Q&A column
was built by committee. ATI Wah Chang Corrosion Lab veteran
Derrill Holmes, welding guru Rick Sutherlin, and chemical
engineer Randy Scheel all contributed. All three are part
of the company’s outstanding Technical Services
team. Brad Webb, ATI Wah Chang’s resident photomicrographer,
supplied the tell tale pictures. Following is a question
that team members are often asked about joining two of
the company’s reactive metals, zirconium and titanium.
Can zirconium be successfully fusion welded
to titanium?
Yes, with some special considerations, it is possible
to weld titanium to zirconium using standard welding processes.
As a matter of fact, it is easily accomplished and results
in a satisfactory weld, but with a few limitations.
Both zirconium and titanium are reactive metals. The mixture
of the two will form a solid solution and be subject to
solid solution hardening. This will cause the resulting
areas of the weld to have different properties from that
of pure zirconium or pure titanium. The weld area versus
that of the pure metals on either side of it may include
differing mechanical properties, formability, impact resistance,
corrosion resistance and other properties.
In some cases, the weld must be heat treated (e.g.: stress
relieved or fully annealed) to improve the corrosion resistance
of the zirconium. In cases where a stress relief heat
treatment is required, the welds can be subsequently heated
to 566°C for up to 4 hours without harm to the weld
(see Figure 1). In cases where a zirconium vessel must
be heat treated, such as concentrated sulfuric acid applications,
we recommend a heat treatment using temperatures from
as low as 625°C for up to 4 hours or at, higher temperatures
such as 788°C, for as little as .5 hours per inch
of thickness.
| Figure 1. Photomicrograph at
8X. Zr-Ti weld stress relieved at 570ºC for 1 hour
(zirconium on left, titanium on right). |
| Figure 2. Photomicrograph at
8X. Zr-Ti weld annealed 625ºC for 1 hour (zirconium
on left, titanium on right). |
| Figure 3. Photomicrograph at
8X. Zr-Ti weld stress relieved at 788ºC for 20 minutes
(zirconium on left, titan |
| Figure 4. Photomicrograph at
150X. Zr-Ti weld annealed 788ºC for 20 minutes (zirconium
on left, Zr-Ti weld on right). |
If a zirconium-titanium weld is present somewhere on the
vessel during heat treatment above 625°C, the weld
can deteriorate rapidly due to unequal oxidation rates
and due to an actual lowering of the oxidation temperature
for each metal as a result of the mixture (see Figures
2 and 3). Notice the deterioration of the weld surface
in each case. Figure 4 shows this deterioration more clearly
at higher magnification.
For an autogenous weld, which will not contain additional
filler metal, the weld itself is composed of 100% titanium
on one side of the weld and 100% zirconium on the other
side. In the weld zone itself, all other alloy compositions
may exist. The composition most sensitive to oxidation
is in the 50:50 concentration range. For the autogenous
weld, this composition range is likely located near the
center of the weld. For thicker sections, the addition
of filler material will be necessary. The composition
of the weld will obviously change depending upon whether
titanium or zirconium is chosen as the filler material.
When fabricating zirconium equipment, external supports
are often welded to the zirconium and bolted to the supporting
structure. The supports do not need to be zirconium because
they are outside of the process fluid. Some fabricators
and designers will propose using titanium for the external
supports as it can be welded to zirconium. Special precautions
should be used when considering this option. There are
at least six special precautions to consider.
- The vessel cannot be heat-treated. From a
practical point of view, even the stress relief
can result in local temperatures above the 566°C
test conditions and may result in excess oxidation.
- In most corrosive media, the weld’s
corrosion resistance is generally less than
that of the pure material (refer to Table 1).
This may indicate fusion welding should not
be used in particular media where process fluids
can contact the weld.
- The mechanical properties of the zirconium-titanium
weld may be much different than that of the
pure metals. The affected mechanical properties
include ductility, strength, and impact resistance.
Failure to account for the physical properties
of the weld may lead to premature failure.
- The mechanical properties of the zirconium-titanium
weld are different than a pure zirconium or
pure titanium weld. The allowable strength values
for zirconium or titanium cannot be used for
calculating strength for applications such as
pressure vessels. The strength of the titanium
band can be used in the calculation, but is
not useful in calculations concerning the actual
weld used to hold the titanium to the zirconium
vessel. The effective zirconium thickness will
be reduced.
- In addition, the presence of the zirconium-titanium
weld on the zirconium plate may result in localized
areas of high stressed. An alternate method
may be to weld zirconium tabs above and below
the titanium band to hold the titanium band
in place. This allows a zirconium-to-zirconium
weld so that the titanium band is not welded
directly to the zirconium.
- Lastly, the possibility exists for crevice
corrosion of the titanium between the supporting
band and the zirconium. Galvanic corrosion is
probably not a concern because zirconium and
titanium are very close on the galvanic series.
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In closing, it’s worth pointing out that there are
other options to fusion welding zirconium to titanium.
One method to avoid the issues mentioned above is to use
explosive bonding technology. With zirconium joined to
titanium in this manner, titanium reinforcing straps could
be employed by welding titanium to titanium.
For more information about working with titanium and zirconium,
including welding and explosive bonding, contact ATI Wah
Chang’s Technical Services team at 888-926-4211.
For our full range of products and capabilities, visit
our web site at www.alleghenytechnologies.com. |
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TECHNICALLY
SPEAKING |
| Versatile Titanium Alloy Proving
its Value |
| By:
John Hebda — Wah Chang |
Over the last two decades, many
new titanium alloys have been patented. Most of these
alloys were developed for very specific applications.
Few, with the exception of Ti-6Al-4V, have been used widely
beyond their specialty applications.
In the Chemical Processing Industries, titanium alloys
developed for corrosive environments have largely been
limited to existing CP titanium and alloy formulations
with palladium, then ruthenium additions. With the introduction
of Allegheny Technologies’ ATI™ 425 titanium
alloy [Ti-4Al-2.5V-1.5Fe-0.25O (oxygen)], that limitation
may be lifting.
Originally Developed
for Armor Plate
The alloy was originally developed for hot-rolled armor
plate to provide ballistic protection comparable to Ti-6Al-4V.
The alloy has been evaluated against a variety of projectile
threats for use as armor. ATI 425 titanium has met or
exceeded the requirements of MIL-DTL-46077F for Ti-6Al-4V
(refer to Table 1). Results of ballistic tests (along
with the corrosion tests discussed later) indicate that
the alloy is very robust.
The alloy might offer a cost advantage over Ti-6Al-4V
since it makes use of lower cost iron as a beta stabilizer
to replace some vanadium.
While processing the alloy for armor plate applications,
it was observed that the material exhibited very good
hot workability, permitting a more lenient window of processing
parameters than necessary for Ti-6Al-4V. The alloy flowed
much easier in forging and rolling than Ti-6Al-4V, was
less prone to surface cracking, and required a far lesser
degree of surface conditioning for subsequent working.
Based on these observations, ATI Wah Chang ultimately
extruded billets (using Ti-3Al-2.5V parameters) into tubular
hollows.
Cold-rolled Mill Products Expand
Potential Applications
The company also produced Ti-4Al-2.5V-1.5Fe-0.25O cold-rolled
sheet and strip products, even given the high oxygen content.
All forms of the alloy exhibited mechanical properties
similar to Ti-6Al-4V, but were slightly easier to form.
The ATI 425 titanium alloy is covered by patents and pending
applications.
Comparisons to Ti-6Al-4V and Ti-3Al-2.5V
The mechanical properties of ATI 425 titanium are very
similar to Ti-6Al-4V. Table 2 provides a summary of the
alloy’s hot rolled plate properties. While the industry
specifications call out minimum values, a more reliable
comparison is found in the Ti-6Al-4V section of The Materials
Properties Handbook: Titanium Alloys from ASM.
The majority of the ATI 425 titanium produced has been
hot-rolled plate. However, other product forms exhibit
a similar range of mechanical property values. ATI Wah
Chang has extruded ATI 425 titanium billet using a process
that parallels its proprietary process for making Ti-3Al-2.5V
seamless tubing.
Since the new titanium alloy flowed well during hot rolling
and forging, we tested whether or not the material could
be cold rolled similar to Ti-3Al-2.5V. Following initial
successes with laboratory-sized coupons in an R&D
facility, larger quantities were successfully rolled on
ATI Wah Chang’s cold mills, capable of handling
sheet and coil (see cover photo of continuous annealed
0.010" ATI 425 titanium foil). Table 3 provides a
summary of the alloy’s cold-rolled plate properties.
A Flexible, Tough Titanium Alloy
ATI 425 titanium has demonstrated good bend ductility.
Cold rolled sheet up to 0.100 inches can be bent to a
radius of 2.5 times the thickness, with the bend axis
in either the longitudinal or transverse direction. Light
gauge, hot-rolled plate (0.1875 inches to 0.250 inches)
can be bent to 3.5 T radius. As with all titanium alloys,
the material must be totally free of alpha case and any
surface anomalies that could become stress risers for
cracking. Bend samples are shown in Figure 1.
| Figure 1. ATI™ 425 Titanium
bend samples. |
Fracture toughness values for plate vary with processing
and anneal cycles. Duplex annealed ballistic plate, with
a relatively coarse but alpha-beta worked microstructure,
averaged four values for a K1C of 78.7. Mill annealed
plate averaged a K1C of 54.6. The fracture toughness obtainable
through a duplex anneal rivals those values only obtainable
via an extra low interstitial (ELI) formulation of Ti-6Al-4V;
however, the Ti-6Al-4V ELI formulations do not have the
strength levels of normal Ti-6Al-4V or ATI 425 titanium
wrought products, such as cold-rolled sheet or small bar.
Results from initial fatigue tests demonstrate that fine-grained
material, such as bar with a high percentage of alpha-beta
reduction, has a much higher fatigue life than the coarse-grained
ballistic plate with lesser amount of alpha-beta work
(~ 50%). In order to optimize one particular property,
such as fatigue life, other characteristics may have to
be sacrificed. Also note that the higher the stress level,
especially as it nears the yield strength, the lower the
fatigue life.
ATI 425 titanium does not appear to be as suitable as
Ti-6Al-4V in elevated temperature applications, such as
internal jet engine components. The elevated temperature
tensile properties were examined to determine extrusion
parameters and compared to Ti-28 (Ti-3Al-2.5V with ~0.1%
ruthenium). ATI 425 titanium appears to have a similar
flow stress to the Ti-3Al-2.5V composition in the TMP
range for extrusion; however, the room temperature properties
in similar anneal states favor ATI 425 titanium with higher
strength levels. Table 4 provides data on the physical
properties of the alloy.
In limited testing, bead-on-plate autogenous welds were
capable of being bent approximately 5.5T after annealing,
with either the root or face of the weld outward. Examinations
of weld microstructures do not indicate any potential
segregation or deleterious precipitates.
Corrosion
Resistant in a Variety of Media
While the initial application of the alloy did not warrant
significant concern over corrosion in a variety of media,
it was understood that armor plate might be exposed to
marine saltwater conditions in amphibious vehicles, shipboard
application, and potentially in some aircraft components.
Initially, the high iron content was a matter of concern
for how the material would respond in certain environments.
ATI 425 titanium performed similar to Ti-6Al-4V in seawater
and hot salt cracking tests; however, at the time of testing,
the alloy had yet to be produced by cold rolling and was
still largely considered an armor plate. Once it was recognized
that ATI 425 titanium had potential for a much wider range
of applications and product forms, additional corrosion
testing was performed on cold-rolled sheet. Corrosion
data is presented in Tables 5-7 (unless otherwise noted,
numbers are given as corrosion rate in mils per year).
ATI 425 titanium continues to prove itself to be a versatile
alloy with higher strength than Ti-3Al-2.5V, nearly equivalent
strength to Ti-6Al-4V and similar corrosion resistant
properties. With the addition of ruthenium and cold-rolled
product availability, it is indeed a unique material.
The ability to obtain a fine, cold-rolled surface finish
and thin-gauge strip product could be desirable for some
applications. ATI 425 titanium exhibits significant corrosion
resistance for a high strength titanium alloy. In addition,
ATI Wah Chang has successfully roll-bonded CP titanium
to the alloy and has also cross-rolled a specimen as well,
which could present opportunities for optimizing both
properties of strength and corrosion resistance.
A Formable Titanium Alloy
A 0.100-inch-thick sample of ATI 425 titanium cold-rolled
sheet used for an Army Research Lab (ARL) trailer bed
project reportedly formed [using superplastic forming
(SPF) technology] in a manner indistinguishable from Ti-6Al-4V
(see Figure 2). The aircraft industry has used this technology
with Ti-6Al-4V to form a variety of complex shapes and
forms that are unobtainable (or too expensive) using other
technology. One advantage offered by SPF technology is
the ability to form a high strength alloy to intricate
detail of small bend radii and large depth/height to thickness
ratio. This technology could be applied in the fabrication
of patterns for Plate Frame Heat Exchanger (PFHE) panels
made from high strength materials — materials that
could not be formed to these patterns using conventional
pressing/tooling technology. It is possible to form PFHE
units with welded panels of a high strength titanium alloy
for applications where temperature and pressure would
have otherwise precluded their use.
Figure 2. The bed for this experimental
trailer was fabricated using
superplastic formed (SPF) ATI 425 titanium. |
Conclusion
While there are significant opportunities for ATI 425
titanium in fracture critical airframe components as well
as cold-rolled formed sheet, this alloy offers some unique
additions to the suite of materials used in the chemical
processing industries. The alloy is robust, of relatively
high strength, yet exhibits reasonable degrees of resistance
to a variety of corrosive media.
| ATI 425 titanium alloy is being considered for
structural components in commercial aircraft. |
ATI 425 offers benefits for pressure vessels, components
of high reciprocating mass, and mechanical members subject
to mechanical damage from inside as well as out. The ballistic
performance cannot be overlooked for containment vessels
where mechanical integrity is critical to the process
or the environment.
While Ti-6Al-4V sheet has rarely been considered as a
construction material in the CPI arena, ATI 425 sheet
in coil form offers potential for screens, honeycomb packing
support, pressure vessels, and possibly plate frame heat
exchangers through the superplastic forming process.
It is rare when a specially developed niche alloy exhibits
such versatility in a wide variety of applications. It
is particularly unusual to have an alloy such as ATI 425,
developed for a non-aerospace purpose, see the potential
to back integrate into airframe and CPI environments.
For more information about versatile ATI 425 titanium
and a full complement of other metals and alloys, contact
ATI Wah Chang at 541-967-6977 or visit www.alleghenytechnologies.com. |
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PEOPLE |
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Recent Changes at ATI Wah Chang |
ATI Wah Chang
is at it again, changing not only the company name but
moving personnel to keep up with customer needs. Starting
immediately, the company most recently known as Wah Chang
will be re-branded as ATI Wah Chang. ATI stands for Allegheny
Technologies Incorporated, ATI Wah Chang’s parent
company.
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Mr. Rob Henson
Mr. Carl Shawber
Mr. Doug Brenizer
Ms. Sue Mose
Ms. Rachel Fletcher
Mr. Barry Valder
Ms. Kandise Kiser
Ms. Carolyn Gardener
Mr. Steve Sparkowich
Mr. Aaron Smith
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In this
spirit of change, longtime ATI Wah Chang salesman
and Corrosion Laboratory veteran, Mr. Rob
Henson accepted a position as the Western
Regional Sales and Marketing Manager for Uniti,
a joint venture company of Allegheny Technologies
and VSMPO. Uniti, the exclusive marketing and sales
arm for Allegheny Technologies and VSMPO for CP
titanium applications, is in position to offer a
package of quality, service and price unequalled
in the industry. Mr. Henson is charged with integrating
Uniti’s order fulfillment process to take
full advantage of the synergies available.
At ATI Wah Chang, Mr. Carl Shawber
will now be responsible for NiTi and medical products
(formerly managed by Mr. Henson) in addition to
continuing his role as Titanium Sales Manager. Mr.
Doug Brenizer, Manager of the CPI Sales Group, will
now manage Castings in addition to his current duties.
Mr. Bill Budd (not pictured) will
join Mr. Brenizer’s Zirconium CPI/Castings
team and will expand his current duties to include
east coast responsibilities for selected CPI accounts.
Other changes in the Sales Department include: Ms.
Sue Mose is moving from the Niobium Sales
Group to manage ATI Wah Chang’s Customer Service
Department. She will supervise the day-to-day activities
and support current e-commerce initiatives. Ms.
Rachel Fletcher will replace Ms. Mose as
Niobium Sales Associate, reporting to Mr.
Barry Valder, Niobium Sales Manager. Filling
Ms. Fletcher’s role in Aerospace Titanium
Sales is Ms. Kandise Kiser, who
was recently promoted to Sales Associate. She will
report to Ms. Carolyn Gardener,
Manager of ATI Wah Chang’s Aerospace Titanium
Sales Group.
Sales isn’t the only department undergoing
changes. Marketing and Business Development recently
added Mr. Steve Sparkowich as Corrosion
Laboratory Manager. Mr. Sparkowich was most recently
a Senior Product Engineer at ATI Wah Chang and has
held process engineering positions at Merix Corporation
and IMI Titanium. In addition, Mr. Aaron
Smith has joined Technical Services as
a Corrosion Specialist. Mr. Smith, a U.S. Marine
Corps veteran, recently received a B.S. in Chemical
Engineering from Oregon State University.
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EVENTS
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Corrosion Conference Recap |
ATI Wah Chang hosted its fourth
international conference, Corrosion Applications 2003,
at Coeur d’Alene, Idaho, September 7-11.
Meeting highlights included Keynote Speeches by Helmut
Diekmann of Bayer, Nicholas Chopey of Chemical Engineering
magazine, Galen Hodge of MTI, and Bruce Craig of MetCorr.
In all, the well-rounded conference featured 45 excellent
presentations and panel sessions on topics ranging from
“Chemical Cycles and the Madness of Cows”
to “Zirconium in Future Applications.”
During a Wednesday evening reception, ATI Wah Chang presented
awards to Conference Keynote Speakers as well as Session
Chairmen Clive Breeden of BP Amoco, John Banker DMC Clad
Metal, Neil Henry of ABB Eutech, Consultant Herman Pieterse,
and Scott Whitlow of DuPont. In addition, Technical Chairman
Rick Sutherlin and Meeting Planner Sheryl Renzoni of Wah
Chang were recognized for their outstanding efforts.
The Organizing Committee thanks its entire team of presenters
for making the Corrosion Applications Conference a success.
In addition, special thanks to ATI’s exhibitor/co-sponsor
group with included Astrocosmos; DMC Clad Metal; Ecodyne
Advanced Metals; Ellett Industries; Flowserve; Harris
Thermal Transfer; H.C. Starck; Joseph Oat Corporation;
Metal Technology; Phoenix; Saint Gobain Advanced Ceramics;
Tico Titanium; Titan Metal Fabricators; Titanium Fabrication
Corporation; Tricor Metals; and The U.S. Department of
Labor. Many thanks to all our conference attendees.
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Stainless Steel World 2003 |
Allegheny Technologies Incorporated
is proud to participate in the 3rd Biennial Stainless
Steel World Conference & Expo, which will be held
November 11-13, 2003 in Maastricht, the Netherlands.
The Expo portion of the event will provide an overview
of the wide range of corrosion resistant alloys for the
oil and gas, chemical, power-generation, onshore, offshore
and pulp and paper industries, welding and stainless steel
fabrication. It’s estimated that 150 exhibitors
and about 3000 visitors from around the globe will participate
in the Expo. Allegheny Technologies will be at Stand #120,
Representatives for ATI Allegheny Ludlum and ATI Wah Chang
will be available to answer any questions regarding the
companies’ corrosion resistant alloys.
For more information on the Stainless Steel World Conference
& Expo, contact Stainless Steel World at ssw2001@kci-world.com
or visit www.stainless-steel-world.net. |
2003 Chem Show |
Allegheny Technologies Incorporated
is pleased to announce that it will exhibit at the 50th
Chem Show, scheduled for November 18-20, 2003 in New York,
New York.
According to www.chemshow.com,
“the 2003 exposition and conference will feature
over 700 manufacturers and suppliers and an anticipated
20,000-plus CPI professionals. Additionally, CHEM SHOW
2003 will offer its most comprehensive conference program
ever, with sessions focusing on four major tracks —
powder processing, process controls and automation, maintenance,
and process integration.”
Representatives from Allegheny Technologies will be on
hand (Booth #1455) to answer any questions regarding corrosion
resistant alloys. The Exhibit Hall location and hours
are as follows: Tuesday, November 18, 10:00am –
5:00pm; Wednesday, November 19, 10:00am – 5:00pm;
Thursday, November 20, 10:00am – 4:00pm.
For more information about 50th edition of the Chem Show,
visit www.chemshow.com.
We look forward to seeing you soon in The Big Apple. |
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LYNN DAVIS
President
PARRY WALBORN
Vice President — Commercial
ANDY NICHOLS
Director of Marketing
GARY KNEISEL
Director of Sales
KIRK RICHARDSON
Editor
Copyright ©2003 Wah Chang. All rights reserved.
Reproduction of this newsletter by any means, in whole
or in part, without written permission is prohibited
by law. Outlook is published quarterly by Wah
Chang. The newsletter contains information on reactive
and refractory metals, including hafnium, niobium, titanium,
vanadium and zirconium, as well as chemicals. The properties
listed herein are average values based on laboratory
and field test data from a number of sources. They are
indicative only of the results obtained in such tests
and should not be considered as guaranteed maximums
or minimums. The starburst logo and Wah Chang are registered
trademarks of ATI Properties, Inc. |
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| Information & Order Contacts |
ATI Wah Chang
(headquarters)
P.O Box 460
Albany Oregon 97321
T 541.926.4211
F 541.967.6990
www.wahchang.com
www.corrosionsolutions.com
Sales/Tech Support
T 541.967.6977
F 541.967.6994
custserv@wahchang.com
CPI Service Center — US
T 541.917.6739
F 541.924.6882
ellen.baumgartner@wahchang.com |
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| Information on Agents/Distributors |
CPI Products
T 541.967.6906
Nuclear-Grade Alloys
T 541.967.6914
Ti, V, and Nb Products
T 541.967.6977 |
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| Affiliated Companies |
ATI Allvac
PO Box 5030
Monroe North Carolina 28111-5030
T 704.289.4511
www.allvac.com
ATI Allegheny Ludlum
500 Six PPG Place
Pittsburgh Pennsylvania 15222
T 800.258.3586
www.alleghenyludlum.com |
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