Metal Forming Success Story
Shiroki NA uses Phygen coating to eliminate
major tool galling when stamping heavy gauge
HSLA parts
The Smithville, TN, facility of Shiroki North
America is a major source of high strength,
low alloy steel parts used in the automotive industry. One
such application is the manufacture of seating assemblies
and component parts used in motor vehicles. Every year there
are hundreds of thousands of front and rear brackets used
in these assemblies. Brackets are stamped out of 590 high
strength, low alloy (HSLA), 1.4mm – 2.0mm-thick steel using
a progressive die in a 600-ton press.
Hinge and bracket components stamped
on die using Phygen coating on forms. |
Ernie Dunkley & Mike Holt evaluating
form tooling with corresponding stamped part. |
According to Ernie Dunkley, Tooling Assistant
General Manager and Mike Holt, Tool
Room Supervisor at Shiroki North America, these
seating assemblies have been in production for about five
years. The brackets measure approximately 50.8mm x 101.6mm
x 76.2mm and undergo a deep draw of 38.1mm to 50.8mm during
a very tight forming operation. Initially this resulted in
severe galling of the tooling.
“We were replacing our forms every three or four months,”
Dunkley explains. “We also were polishing them after every
run. The results were unnecessary rework and sorting. In an
effort to correct this problem, we implemented several Kaizens.”
Using a Three-Step Approach
"The first step we took was to evaluate the current
type of lubricant being used,” Dunkley says. “We switched
to an Irmco lubricant specifically formulated for high strength
steel per the recommendation of Ken Heindrichs of Productive
Stamping Solutions, Inc. We had some success but still focused
on continuous improvements. Next, we began to evaluate the
coating being used on the tools. After a couple of tries,
it was in this area that we had the greatest success.”
“Initially, we tried a thermal diffusion (TD) coating,”
Dunkley reports. “We had prior experience using that type
of coating but in this particular case it didn’t work out
too well. Just like the lubricant, the coating provided us
with some benefit but not enough. After changing lubricant
and applying a TD coating to the tooling, we saw an improvement
of about 50 percent.”
“We still had to inspect a percentage of the parts,” says
Dunkley. “The TD coating started out doing a good job but
didn’t hold up to expectations. We’d start out with the new
coated tooling and the first one or two runs we’d hardly have
any issues. But then, after two or three runs, we’d started
to see galling and we had to go back to inspecting parts as
before.”
“We’re talking about 6,000 parts per run,” Dunkley explains.
“So, after running about 12,000 to 18,000 parts with the TD
coating, the tooling began to gall sufficiently that we had
to resume reworking the parts. Our next step was to try the
Phygen FortiPhy™
coating.”
Attend PMA Show
Bracket die strip off die using Phygen
coating showing no signs of galling. |
Shiroki North America heard about
Phygen UltraEndurance™ coatings through Ken Heindrichs
(right) of Productive Stamping Solutions, Inc. |
Dunkley and Holt from Shiroki North America say they heard about
Phygen coatings through Ken Heindrichs, but did not meet the
Phygen staff until Heindrichs introduced them at the PMA show
in Nashville. “We went to the show specifically to look for
other coatings that might be able to solve our problem,” Dunkley
explains. “We stamp a lot of high strength steel here and we
were looking to see if anyone had any new ideas on how we could
solve our tooling issues. We contacted Phygen concerning our
tooling issues and they had a lot of good ideas.”
“It just so happened, at that time we had a new die to produce
a door part, on which we really had to expedite the lead time,”
Dunkley continues. “We stamp the part here and ship it to
our Georgia facility where it is used in the door assembly.
We were going to coat the die with a TD coating, but this
would require about a two-week (10- to 14-day) turn around.
Customers wanted us to reduce the lead time and have the die
ready as soon as possible. When we talked to Phygen at the
show, they were able to promise us a three-to-four day turn
around. They picked up the form, applied the coating, and
had it back to us in three days. Best of all, the FortiPhy
coating worked extremely well.”
“Based upon that experience, we decided to apply the FortiPhy
PVD coating on the bracket dies, and we had a great deal of
success,” Dunkley says. “I had the forms coated and let the
toolmakers in the tool room tell me if it was a success.That’s
where the true measure of success comes from. They loved it.
They couldn’t believe it.”
Going Strong After Six Months
“If you talk to our tooling people,” Holt says, “you’ll
find they have been very impressed with the Phygen coating.
It took a lot of pressure off them. We sent the form out and
had it coated about six months ago, and we haven’t replaced
that form yet.”
Ernie Dunkley standing at press pointing
to station that has Phygen coated forms. |
“Now, when we finish a run and send the tooling to the tool
room,” he continues, “we don’t even have to polish it. We
just wipe it off and send it back to the pressroom. During
the six-month period since we’ve had it coated, the tooling
has produced about 120,000 pieces. The coating is still in
good condition and we have not had to do any rework on the
brackets produced with the FortiPhy coated dies.”
In addition to eliminating the 100% inspection of the brackets,
Dunkley says they’ve also saved a significant amount of die
maintenance time, plus a tremendous amount of downtime--not
only in the pressroom, but also on the assembly line. “We
run on a just-in-time basis,” he explains, “so if we run a
part that we have to rework and/or sort, we could be running
so close that the assembly line might have to be shut down
because we don’t have any parts to supply it. This means that
we would have four or five people waiting for parts and the
cost of this lost time adds up very quickly.”
Part rework and/or sort savings can amount to several thousand
dollars per month, Dunkley estimates. “We’ve significantly
reduced this cost. It used to be our number one item.”
“On the new die for the doorframe part, which Phygen coated
for us in just three days, we inadvertently double stacked
that form and we were all just horrified,” Holt says. “We
sent a toolmaker to the press to look at it and the first
words out of his mouth were ‘I think the coating broke down.’
But after the die was in the tool room and the forms were
wiped off, it was just fine. So even with a double stacked
part, the Phygen coating held up. A lot of coatings would
have been ripped right off.”
Tool Coating Benefits
“We’ve begun to Yokoten other dies using the Phygen FortiPhy
coating and we’re seeing similar results to those we’ve experienced
with the bracket tooling,” Dunkley says.
“We are continually on the lookout for better ways to do
things. For instance, we have a restrike station on this job
and we are going to go ahead and coat that too. Overall, the
benefits we’ve seen with the Phygen coating on the bracket
dies include an improvement in part quality, reduced downtime
on both the press and production lines, and greatly reduced
tooling cost.”
FortiPhy Coatings – At a Glance
FortiPhy™ CrN UltraEndurance™
coatings from Phygen Coatings, Inc., are the result of using a
patented plasma acceleration process to apply ultra endurance
coatings. This increases durability and toughness while reducing
friction, wear, and corrosion. FortiPhy coatings have vastly
superior adhesion, structure, uniformity, and density compared
to other commercial coatings. The Phygen process delivers
a more energetic plasma to create a coating that consists
of nano-sized particles. This produces a more uniform, anocrystalline
microstructure, for the toughest coatings possible. Lower
processing temperatures keep critical part dimensions within
tolerance, for less rework. Extremely good process control
and management of coating thickness allows Phygen to custom-tailor
coatings for specific applications.
More On the Company…
“The performance leader in surface enhancement,” Phygen Coatings, Inc. specializes in hard facing and surface treating of tooling
and equipment for metal forming applications (as well as a
broad range of other markets – die casting, plastics, etc.).
Phygen’s FortiPhy™ UltraEndurance™
Coating provides protection from wear and corrosion. Other
coatings available from Phygen include:
- VeriPhy™ Coating –
a gold colored titanium nitride TiN based coating developed
specifically as a cost effective work-horse coating.
- CertiPhy™ Coating
– a dark violet surface enhancement targeted on high value
tooling. This coating provides a top notch graded architecture
of nanolaminated layers of titanium and titanium aluminum
nitrides (TiAlN) which possesses extremely high resistance
to heat checking and soldering.
For more information, contact Phygen Coatings, Inc., 1400 Marshall
St., NE, Minneapolis, MN 55413, Phone: 888-749-4361, Fax:
612-331-4230.
|
