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Winsert's single focus pays off: Wisconsin-based Winsert casts valve seat inserts, but beats the competition with its alloy development and in-house testing systems.

Three words define Winsert Inc., Marinette, Wis.--valve seat inserts. Accounting for more than 95% of its product base, cast and machined valve seat inserts for diesel, gasoline and gas engines are the bread and butter for this 125-employee firm.

So, how do they do it? When every independent metalcasting facility screams the importance of diversification and not putting all your eggs in one basket, how does Winsert succeed and thrive with one main product?

The answer is product performance. The answer is that Winsert has made manufacturing a value-added component of its valve seat inserts and placed the importance in alloy development and testing.

Valve seat inserts are circular components placed in engine cylinder heads where the valve comes in contact with the head. Located at the intake and exhaust ports of the combustion cylinder, valve sear inserts must perform reliably under seating pressures up to 3,400 psi and operating temperatures that can reach 1,500F (815C) on the seating surface of the valve. As heavy wear components designed to extend the life of the cylinder head, valve seat inserts typically are manufactured from cobalt-, nickel- and iron-based alloys to extend service and wear life as long as possible.

For Winsert, wear is the point at which it tries to shine. While typical metalcasters say their cast components outlast the life of the end-product. Winsert knows its inserts are going to wear out. The firm's goal is to extend that life as long as possible. This is accomplished utilizing the strength of its research and development department in generating new' heat-and wear-resistant alloys and performing wear testing in combination with its unique casting process for high production at low costs.

The success has been noticed by its customer base. In the last six months, Winsert received a "Supplier of the Year" award from Detroit Diesel Corp. (for the third consecutive year) and 'supplier-excellence" recognition from John Deere Power Systems (for the third consecutive year).

"With consolidation shaping our customers' industries and the firms we supply, we understand that it takes more than a good cast insert to stand out from the competition," said Trisha LaVia, executive vice president. "We must be a total supply solution."

This article examines Winsert's cast insert production and takes a look at how the firm utilizes its one-product focus for success.

Stack Molding

For the casting side of the operation. Winsert employees 13. These workers produce 11 million cast inserts per year. As shown in Fig. 1, an insert is as simple looking a casting as any However, the simplicity in shape hides the complexity of the manufacturing used to produce it.

[FIGURE 1 OMITTED]

Winsert has refined a unique stackable shell mold casting process to allow its "commodity" components to be produced cost-effectively. For casting, circular sit-ell molds are formed on one of six core machines. Each mold piece forms the drag lot one casting and the cope for another (except the first and last mold pieces, the end caps, which have one side that is flat).

These shell mold pieces are stacked (Fig. 2) in one of 100 racks to a maximum height of 15 to form the molds for pouring. Glue is applied between the molds to ensure each stack's stability due to the molten metal pressure. Each pair of mold pieces produces from 2-50 circular cast valve scat inserts. Winsert produces an average of 80 mold pieces per hour for each shell mold machine operator, usually running two operators on the mold machines lot 20 hr/day.

[FIGURE 2 OMITTED]

For Winsert, the limitation on metal height is twofold. The first is that the higher the stack of molds, the more difficult the pour is. Second, the pour height can be too violent on the alloys the firm casts. To reduce molten metal turbulence, Winsert uses filters at the base of the downsprue before the metal flows to the up-sprues that feed the runners and ingates for each casting tree. The complexity of these gating systems produce an average yield of 65%, but the firm believes this low yield is necessary to ensure quality.

"We are trying new techniques with double filtering of the molds to in crease quality and yield," said Kevin Myers, vice president of engineering and product development. "But at the level of production we are performing with a large variety of alloys, we need to keep mold production as consistent as possible."

For the average metalcaster, the best way to envision this mold process is to compare it to high-production investment casting with a central downsprue and trees of component after shakeout. Because of the lower component cost, shell sand casting allows for simply designed components in conjunction with fine surface finish. However, Winsert does have concerns in the casting process beyond controlling metal flow via filters.

One of the keys to valve seat inserts is that the seating surface on the casting (and the points adjacent to it) can have zero casting defects. As a result, the inserts are positioned in the mold upside down to have the critical points at the bottom of each mold cavity to ensure the highest quality metal at the seating surface. Gas, sand or slag defects will rise to the top of each casting and will be machined off during post-casting processing.

Shakeout for Winsert is a typical dump operation with mechanical assistance and then manual knockoff of the castings. The castings then proceed to the in-house grinding, machining and testing operation. Typically, a cast insert makes it through the metalcasting operation in 1.5 days.

"While the value of our valve seat inserts doesn't rest in the metalcasting operation, the castings still must leave the operation without defects in the critical areas," said Myers. "Just because our machining operation is in-house doesn't mean that any problems in casting are any easier to accept."

For Winsert, 20% of the value of its valve seat inserts is seen from the casting operation. However, the foundation of quality does begin in metalcasting. In the firm's competition with high-alloyed powder metal inserts, casting allows it to produce inserts at a modest cost advantage.

Alloys

Winsert melts in two 750lb. electric induction furnaces. Pouring directly from the furnace, Winsert pours 10-14 mold stacks per heat, As a result, the firm melts a new heat every 45 min. These small heats are required due to the number of different alloys the firm pours.

Winsert lists 24 different alloys on its capabilities as the most specified, but still specializes further to meet its customers' needs. Since 1997, Winsert has developed 14 new alloys for its cast valve seat inserts.

For Winsert's three main groups of alloys:

* cobalt-base alloys provide superior resistance to abrasion, corrosion, oxidation and sulfidation. In addition, they provide excellent dimensional stability at all temperatures and hot hardness to 1,600F (871C);

* nickel-base alloys provide excellent dimensional stability for applications subject to corrosion, oxidation and high temperatures. They provide fair abrasion resistance and machinability as well as offering good hardness at temperatures up to 1,500F (816C):

* iron-base alloys provide good mechanical characteristics at a low cost for applications not subject to overheating [1,200-1.400F (649-760C)]. In addition, these alloys offer good abrasion resistance and are highly machinable.

"It used to be you could quote essentially the same materials for most engine applications," said Gary Strong, vice president of applied metallurgy. "Today, what has changed probably more than anything is the engine environment due to new emissions standards. Many of the materials that used to work just don't anymore. It truly is a continuous improvement process."

In looking toward continuous improvement, Winsert recently completed a 3000-sq-ft. expansion to its facility, much of which was dedicated to the firm's research and development department, For Winsert, this is the focus of its future drive. The firm believes its manufacturing (casting and machining) with continuous improvement and automation will always compete in the global environment. However, what sets it apart is its alloys and the better product they help to provide.

While often driven by its customers and what their needs are for wear resistance, Winsert knows the competitive cost and quality advantage it can gain by developing its own alloys. With its in house testing facility, the firm is able to study chemistry, formulating new casting specimens to perform in-house tests almost immediately. Winsert has designed and built in-house test machines for hot hardness, pin on disk, pulse load wear simulation and thermal expansion.

The pulse load wear testing system (Fig. 3) is the firm's most advanced as it performs practical, application tests that simulate true engine test results, not lab test results. Pulse testers use the principle that in practical systems, valve seat insert wear stems from sliding and normal contact of the valve on the insert. The tester simulates both these types of motion using the movement of two parts.

[FIGURE 3 OMITTED]

"We made the decision very early that if we were going to develop new materials, these test capabilities would need to be in-house to reduce analysis times," said Strong.

Ready for Shipment

While this article will not feature the machining operation at Winsert, the firm has specialized and automated this side of the operation to take the cast inserts from shakeout to heat treat to grinding off the gates and outer and inner diameters to finish machining.

To complement the finishing operations and add to Winsert's branding as a full-service supplier, the firm has 100% inspection on its cast inserts, including visual and liquid penetrant inspection. However, to improve its inspection capabilities anti increase automation, Winsert added a new key to its inspection Process--an automated defect-recognition inspection system capable of inspecting up to 3,000 cast inserts/hr (Fig. 4)--in 2003.

[FIGURE 4 OMITTED]

The automated inspection equipment allows production increases without additional staff.

"We are focused on zero defects for the cast inserts we ship, "said Myers. "This isn't just a statement, and this automated inspection system is making this a reality."

The system works by turning each surface of the cast insert into a bitmap digital image. The system then con> pares these images to the reference image and then recognizes if defects are in the critical or non-critical areas of the machined castings. From there, a cast insert is accepted or rejected.

For Winsert, the acceptance or rejection of its cast inserts really begins back in the research and development process for its alloys. This is the foundation of its cast components. In reality, for Winsert, the casting, machining and testing operations are all just value-added services to augment the alloys that provide the wear-resistance required for its cast valve seat inserts.
Winsert, Inc,
Marinette, Wisconsin

Year Founded: 1977

Alloys: Iron-, cobalt- and nickel-base
 alloys.

Process: Shell (no cores).

Markets: Valve seat inserts for
 diesel, gasoline and
 natural gas engines

2003 Production: 11 million cast and
 machined valve seat
 inserts.

Value-Added
Services: Heat treat, machining, full-service
 testing and alloy development.

Size: 61,000 sq. ft.

Employees: 125.
COPYRIGHT 2004 American Foundry Society, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2004, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

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Comment:Winsert's single focus pays off: Wisconsin-based Winsert casts valve seat inserts, but beats the competition with its alloy development and in-house testing systems.
Author:Spada, Alfred T.
Publication:Modern Casting
Article Type:Company Profile
Geographic Code:1U3WI
Date:Mar 1, 2004
Words:1833
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