Chrome Carbide Overlay (CCO) Wear Plate ... - JADCO Manufacturing

Chrome Carbide Overlay (CCO) Wear Plate, made by machine welding hard facing on a mild steel base plate, is normally the best choice for combating abrasion applications.

You will get efficient and thoughtful service from JINHUA HARDFACING.

Have you previously had difficulty using CCO wear plate?

Evaluating our customer/client comments over many years, we know most issues can be traced back to three (3) common installation mistakes.

Most CCO wear plates are welded into place and welders, in general, use the following two (2) types of welds:

1. Joining Welds – which retain the CCO plate to the base plate of the equipment. Joining welds are not as hard as the Chrome Carbide, and abrasion can rapidly wear away the joining weld deposit.
2. Hardfacing Welds – these join nothing. The only purpose of a hardfacing weld is to cover or ‘Cap’ the joining weld. This protects the weld from wear in the same way as a hat protects your head from the rain.

It doesn’t matter if you are using stick or wire feed welding, the process is still the same.

THE 3 MOST COMMON MISTAKES

Mistake # 1: Not hardfacing a cap over the joining welds.

The ‘A’ shows how the joining weld has worn away. This was caused by not hardfacing a cap over the joining welds. This issue will result in premature failure and unplanned downtime.

The  ‘B’ shows what happens when the edge of the CCO plate is exposed to the abrasive elements. The mild steel backing plate is not hard and will quickly wear away. Without the base for support, the carbide surface falls away; leaving no abrasion protection, resulting in premature failure and unplanned downtime.

Mistake # 2: Not hardfacing or capping the structural welds retaining the overlay plate. 

Not hardfacing or capping the structural welds retaining the overlay plate. This is the primary cause of most CCO failures. It is important to understand joining welds are NOT HARD LIKE THE OVERLAY surface. This means the weld joint does not have the same abrasion resistance as the CCO deposit. The abrasion material flow is now able to get behind the wear plate and create a hole through the equipment structure.

DO THIS for a successful installation:

After all welds have secured the wear plate, apply a hardfacing alloy to cover all joining welds. This will protect the joining weld deposit keeping your steel plates in position.

Allowing the edge of CCO to be exposed. NEVER allow the edge of a CCO plate exposed to abrasive elements. The mild steel backing plate for the CCO deposit is not hard and wears away rapidly.

 The Chrome Carbide Overlay is there only for wear resistance. This means the overlay has no structural integrity by itself. That is the overlay’s only job. When the softer mild steel base plate has worn away, there is no support for the overlay. Like a violent flood causes a river bank to fail; the carbide surface will tumble into the abrasive flow. This leaves you with zero protection, resulting in another premature failure and unplanned downtime.

For A Successful Installation YOU MUST DO THIS: More critical than the weld joints, ALL exposed CCO plate edges MUST be covered with a compatible hardfacing alloy. Preferably use the same deposit as the overlay; being certain to cover all edges of the CCO wear plate.=

Remember to cap all the plug welds with hardsurfacing so they do not wear away, allowing the plate to flex; leading to failure.

JADCO Mfg., wants your investment in the finest wear resistant CCO material to last as long as possible.  This is why we want you or your contractor to know exactly how to install these plates.  Don’t expect the contractor has experience installing CCO wear plate.

For your unique applications, we have five different versions of CCO plates:

• Chromeweld 600 – Chrome Carbide; high carbide concentration for most applications
• Chromeweld Nb Plus – Chrome and Niobium Carbides; for fine particles and high velocity
• Chromeweld Ti – Chrome and Titanium Carbides; for abrasion with impact
• Chromeweld Complex – Chrome, Niobium and Vanadium Carbides for extremely demanding applications including high heat.
• Chromeweld W – Chrome and Tungsten Carbides; RECENTLY INTRODUCED BY REQUEST TO COMBAT YOUR most aggressive wear challenges.

Uncertain which CCO wear resistant plate is the best for your application? Listen as JADCO’s president Sam Anderson explains these four different CCO platesin this YouTube video; allowing you to make an informed decision which product is best for your unique application.

We Understand You Don’t Buy Wear Plate Because You Need Wear Plate…You Buy The Correct Wear Plate To Provide Longer Equipment Life For Your Unique Application. 

JADCO sales professionals focus on delivering results FOR YOUR MOST CHALLENGING WEAR APPLICATIONS. 

By focusing exclusively on delivering longer life and consistent value for our customers over the last 40 years; JADCO is able to deliver greater performance in your applications.

Allow us to help you by calling (724) 452-, or today. We will schedule a meeting with one of our local wear plate specialists at a time that best fits your schedule requirements.

Hardfacing improves the service life and efficiency of metal parts that are subject to wear. Simply choosing the right product will not guarantee a good result. The base metal, wear mechanism, welding process, and application details are all equally important factors. Here are 25 guidelines that will assist in maximizing the benefits of your hardfacing applications. 

Base Metal Considerations

1. Identify the base metal along with its carbon and alloy contents. Common base metals include carbon steels, low-alloy steels, manganese steels, austenitic (AISI 300 series) and martensitic (AISI 400 series) stainless steels, tool steels, and cast irons.

2. Preheating is required for higher-carbon and low-alloy steels, tool steels, martensitic stainless steels, and most cast irons. Preheating minimizes distortion and cracking and mitigates the thermal shock. Carbon and alloy contents determine preheat temperature.

3. With higher carbon and alloy steels, an abrupt cooling to ambient temperature embrittles the heat-affected zone. The cooling rate should be controlled in an oven. Other means, like a fireproof blanket or a vermiculite box, are also used.

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4. Manganese steels do not require preheating besides warming up to 80°F (26.7°C). They become brittle if the base metal temperature exceeds 500°F (260°C). Avoid applying prolonged and concentrated heat. Consider water cooling.

5. When rebuilding manganese steels, remove 1/8 in. (3.2 mm) of the fatigued work-hardened surface. Failure to do so may result in underbead cracking. Also avoid using carbon steel buildup filler metals upfront. An austenitic steel buffer layer is advised.

Wear Factor Identification

6. Low-stress abrasion, or two-body abrasion, is the most common wear mechanism. It’s typical of mineral bulk handling and ground-engaging tools. Higher carbide content and harder hardfacing deposits are usually the most cost-effective solutions.

7. High-stress abrasion, or three-body abrasion, involves a crushing action, typically found in milling or fine-grinding operations. Tougher hardfacing materials with well-dispersed carbides would usually be specified.

8. High-energy impact, gouging wear, and heavy rolling imply plastic deformation and call for work-hardening deposits, like austenitic manganese steels. This is the case with primary crushers, scrap yard shredders, and railway frogs.

9. Adhesive wear or galling is typical of metal-on-metal friction under heavy loads. A homogeneous alloy steel or tool steel is usually the hardfacing choice. Well-known applications include undercarriage rollers and hot strip mill rolls.

10. Corrosion is a synergy factor for the wear mechanisms above. Wet process conditions are not necessarily a concern, but as the acid concentration increases (pH < 7), nickel- or cobalt-based alloys may become necessary.

11. Temperature is another synergy factor. Iron-based hardfacing deposits, including the chromium carbide overlays, see a significant hardness drop around °F (538°C). Using a nickel- or cobalt-based alloy is an option. Thermal cycle fatigue and fire cracking are also concerns.

Filler Metal Selection

12. If dimensional restoration is needed prior to hardfacing, select a buildup material compatible with both the base metal and the final weld overlay. The chosen buildup should provide sufficient mechanical properties for the application.

13. The hardness of a hardfacing deposit is not the deciding wear-resistance factor. The percentage, characteristics, and distributions of the carbides throughout the alloy or matrix determine how well a hardfacing will resist specific wear conditions.

14. Where abrasion resistance is the primary requirement, with low-to-moderate impact, and filler metal cost is a concern, using a chromium carbide overlay is usually a good option. This is the most common hardfacing solution.

15. Chromium carbide overlays tend to cross check as they cool, producing fine cracks across the bead. This beneficial cracking pattern relieves residual stress. However, any irregular patterns, like longitudinal or underbead cracking, will lead to spalling.

16. Tungsten carbide hardfacing resists extreme mineral abrasion the best. A nickel matrix is ideal for minimizing carbide dissolution. The tungsten carbide content increases with cored wire diameter. The highest contents come with plasma transferred arc welding and laser cladding.

Welding Process Optimization

17. Select the welding process best suited for the application, balancing the dilution level with the deposition rate as well as other concerns, such as geometry, occupational safety, or automation requirements.

18. High levels of base metal dilution reduce wear resistance and the carbide fraction in the deposit. To keep the dilution rate to a minimum, a good practice is implementing lower welding settings and controlling heat input.

19. Chromium carbide overlays imply heat input control. Some base metal dilution is required for a lesser-
alloyed transition zone and to avoid underbead cracking — Fig. 1. This transition shall make up 25% of the weld thickness. On the other hand, too much heat input would compromise the desired primary carbide microstructure — Fig. 2.

20. When using open arc wires (flux cored arc welding), the stickout, or contact-tip-to-work distance, is critical. A stickout shorter than ½ in. (13 mm) will cause porosity. Small-diameter wires typically weld at a 5/8- to ¾-in. (16- to 19-mm) stickout. Large-diameter wires require a longer stickout between ¾ and 1¼ in. (19 to 32 mm).

21. Submerged arc welding fluxes affect the chemistry, hardness, bead shape, and surface aspect of the weld. Use the correct flux and wire combination. Use new and properly screened flux to prevent chemical variations. Flux overburden or an excess of fines will result in trapped gas, porosity, and surface defects.

Application Recommendations

22. If a worn part shows leftover hardfacing, you can 1) apply one additional layer of a similar material if the existing layer is sound and thinner than 1/8 in. (3.2 mm), or 2) remove the old hardfacing down to the sound base metal, especially if deep cracks are present, by using either carbon arc or plasma gouging before finish grinding.

23. A cost-saving alternative to hardfacing an entire surface is to apply weld bead patterns. Beads applied perpendicular to the abrasive flow work well for fine materials, like sand or soil. Coarse materials require beads parallel to the flow. Such beads act as runners, allowing the burden to ride along.

24. Grinding sharp corners is recommended. A hardfacing applied along a sharp edge may indeed break off under impact. Applying the hardfacing into grooves cut into impact-resistant support may also help under high impact.

25. Applying a crack-free cobalt-based hardfacing, like the Stoodite® 6-M (ERCCoCr-A), requires specific precautions. A two- to three-layer AISI 309L stainless steel buffer is often advised to match thermal expansion coefficients. Preheat should be at least 600°F (315°C), independently of the base metal, sometimes even up to 900°F (482°C).