Vecalloy 700 - Polymet Technical Datasheet

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Vecalloy

700

Technical Datasheet

PRODUCT OVERVIEW

Vecalloy 700 has been specifically designed to perform in aggressive environments possessing both abrasive wear and impact. It meets a unique materials requirement in that it possess the high abrasion resistance similar to tungsten carbide based solutions (WC PTA) and high impact toughness over 500X that of WC PTA.

In order to achieve this goal, computational metallurgy has been used to create an Fe-based alloy which inherently grows tungsten boride particles which are on the order of 100-200X s m a l l e r t h a n t h e W C p a r t i c l e s u s e d i n conventional PTA.

DESIGN APPROACH

The design process for Vecalloy involves a proprietary high throughput computational metallurgical process to evaluate millions of candidate alloy compositions. Potential candidates are then experimentally evaluated using an advanced screening process where both properties and alloy microstructure are measured.

The combined computational and experimental approach allows us to rapidly design the final material with a much better accuracy than conventional experiment-based methodologies.

VECALLOY 700 CHEMISTRY AND PERFORMANCE

Material Chemistry (wt%)

Vecalloy 700

at 2,500X

B C Cr Nb Ti W Other Fe

<4 <4 <30 <10 <10 <20 <10 Bal.

‣ ASTM G65A: 0.08 – 0.12 grams lost (low stress abrasion)

‣ Jaw Crusher Test: 0.217g lost (high stress abrasion)

‣ Hardness: 62-65 HRC

‣ Impact Resistance: 0.003-0.01 grams lost (after 3,600 8J Impacts)

Vecalloy 700 has been designed to outperform Tungsten Carbide, Nickel Matrix (WC-Ni) Plasma Transferred Arc Solutions. The most critical limitation, and thus the property which governs the lifetime of WC-Ni PTA coatings, is the poor impact resistance or toughness. Vecalloy 700 exhibits an impact resistance over 500 times that of WC-Ni PTA coatings, while also maintaining a similar abrasion resistance.



Vecalloy

700

Technical Datasheet

WHY VECALLOY 700 OUTPERFORMS WC-Ni PTA

Homogeneity: Unlike a PTA coating which effectively involves depositing two separate materials simultaneously, a Ni matrix and WC particles, Vecalloy 700 is deposited as a single alloy which naturally grows a network of carbide and boride fine-scale precipitates.

Whereas WC may sink or float in a molten weld pool resulting in varied performance through the thickness of the weld, the Vecalloy 700 carbide and boride network are thermodynamically driven to precipitate at equal concentrations throughout the weld thickness.

Notice in the micrographs on the following page how the WC particles are clumped together in some areas of the weld and some sections are free of WC particles in the WC-Ni PTA coating. Whereas, the carbide spacing is thermodynamically driven to a very precise spacing in the Vecalloy 700 weld.

Fine-Scale Microstructure: WC PTA coatings typically use carbide particles on the order of 50 to 200 microns in size.

Notice how large carbides can be seen in the WC PTA micrograph on the following page, but at 500X it is very difficult to see the carbides in Vecalloy 700. Only in the 2,500X micrograph on the cover page can the tungsten borides and carbides in Vecalloy 700 be seen clearly.

Unlike typical WC PTA applications, the carbides a n d borides in Vecalloy 700 are thermodynamically grown in the liquid alloy and thus are always consistent in size, shape and distribution. This fine scale microstructure has many beneficial effects such as preventing small sand particles from attacking the matrix directly, and distributing thermal stresses more evenly upon cooling.

However, perhaps the most important benefit of the Vecalloy 700 microstructure is the ability to withstand impact and high stresses. Almost every application which is commonly understood to be an abrasive environment is also an e n v i r o n m e n t c o n t a i n i n g h i g h s t r e s s a n d significant levels of impact.



Vecalloy

700

Technical Datasheet

In the micrograph (right) the WC particles are

clumped together in some areas of the weld and

some sections are free of WC particles in the WC- Ni

PTA coating. Whereas, the carbide spacing is

thermodynamically driven to a very precise

spacing in the Vecalloy 700 weld.

Carbide

Rich

Carbide

Depleted

Notice too, large cracks (highlighted by the white arrow) running through the microstructure of the 25X WC PTA coating.

Large carbides can be seen below in the WC PTA

micrograph, but at 500X it is very difficult to see the

carbides in Vecalloy 700.

Only in the 2,500X micrograph on the cover page can

the tungsten borides and carbides in Vecalloy

700 be seen clearly.

Crack WC PTA

at 25X

WC PTA at

500X

Vecalloy 700 at

500X



Vecalloy

700

Technical Datasheet

Ma

teria

l L

oss

(g

)

HOW VECALLOY 700 OUTPERFORMS WC-Ni PTA & CHROMIUM CARBIDE

Many people are surprised to see that despite Vecalloy 700 testing at slightly less abrasive resistant than WC PTA coatings, the Vecalloy 700 significantly outlasts WC PTA in actual application. The answer lies in the revolutionary improvement in impact resistance.

While WC PTA is well known as the standard for abrasion resistance under ASTM G65 testing, relatively low levels of impact can generate cracks and significant levels of material loss. As shown in the diagram below when subject to 30 minutes of wear (ASTM G65) all of the coatings exhibit very minimal material loss. However, after 30 minutes of impact, the WC coating exhibits a accelerated levels of material loss. Therefore, depending on the application, a greater level of concern should be placed on improving impact resistance than on abrasion resistance.

How can we define the level of impact that one should pay attention to? This particular impact test is standardized to 8J of impact energy, the amount of energy developed by dropping a 2 lb. rock a distance of 3ft. It stands to reason that many more applications should consider the use o f c o a t i n g s o l u t i o n s w i t h b e t t e r i m p a c t resistance. Vecalloy 700 has an impact resistance over 500X that of WC PTA or Chromium Carbide solutions.

Impact and Abrasion Testing Results of Wear Resistant Coatings

15 14

Wear Loss Impact Loss

11.25

7.5

3.75

0

3.25

1.5

1.75

0.003

WC-NiCrSiBFe WC-NiSiB CrC (High Carbide)

CrC (Low Carbide)

Vecalloy 700



Vecalloy

700

Technical Datasheet

SUGGESTED APPLICATIONS

Vecalloy 700 coatings are suggested for use in any applications where abrasion resistance is required. The revolutionary improvement in impact resistance and toughness will typically result in an extended lifetime over WC PTA and Chromium Carbide coatings.

Specific applications include:

‣ Shaker Screens

‣ Grader Blades and other Ground Engaging Tools

‣ Chute Blocks

‣ Pipe I.D.

‣ Other Mining Applications

CASE STUDY: SHAKER SCREENS

Vecalloy 700 was run in a side-by-side comparative field trial in the oil sands of Alberta. The Vecalloy 700 screen showed a 3X increase in screen lifetime. The adjacent WC PTA screen required two on-site reapirs due to spalling of the coating, the Vecalloy 700 did not require any repairs.

This application is a good example of how Vecalloy 700 can be effectively utilized in abrasive environments which also contain impact to improve component lifetime at reduced component cost.

HOW TO USE VECALLOY 700

Vecalloy 700 is currently available in 1/16”, 3/32”, and 7/64” metal cored wire as well as 53-150µm powder for Plasma Transferred Arc (PTA) welding or Laser welding. Additional welding wire diameters are available upon request.

The suggested welding parameters and expected results for Vecalloy 700 are provided on this page and the following pages.

Vecalloy 700 1/16-inch GMAW WELDING PARAMETERS

Wire Diameter 1/16 in (1.6 mm) 1/16 in (1.6 mm) Current DCEP DCEP Desired Weld Thickness 3 - 4 mm 6 - 8 mm Voltage 26 - 29 26 - 29 Amperage 250 - 280 250 - 280 Shielding Gas Ar 100%, Ar 98%/O2 2% Ar 100%, Ar 98%/O2 2% Stickout 1 - 1.25 in (25 - 32 mm) 1 - 1.25 in (25 - 32 mm) Preheat 300 - 400F (150 - 200C) 300 - 400F (150 - 200C) Torch Drag Angle 5 - 15° 5 - 15° Travel Speed 7 - 15 in/min 3 - 5 in/min Expected Hardness 62 - 65 HRc 62 - 65 HRc Expected ASTM G65 mass loss 0.08 - 0.12 g 0.08 - 0.12 g



Vecalloy

700

Technical Datasheet

HOW TO USE VECALLOY 700 (cont’d)

Vecalloy 700 3/32-inch GMAW WELDING PARAMETERS

Wire Diameter 3/32 in (2.4 mm)

Current DCEP

Desired Weld Thickness 6 - 8 mm

Voltage 28 - 30

Amperage 340 - 380

Shielding Gas Ar 100%, Ar 98%/O2 2% Stickout 1 - 1.25 in (25 - 32 mm)

Preheat 300 - 400F (150 - 200C)

Torch Drag Angle 5 - 15°

Travel Speed 4 - 8 in/min

Expected Hardness 62 - 65 HRc

Expected ASTM G65 mass loss 0.08 - 0.12 g

Vecalloy 700 7/64-inch SUBMERGED AND OPEN ARC WELDING PARAMETERS

Wire Diameter 7/64 in (2.8 mm)

Current DCEP

Desired Weld Thickness 6 - 8 mm

Voltage 28 - 30

Amperage 480 - 510

Stickout 1 - 1.5 in (25 - 38 mm)

Preheat 300 - 400F (150 - 200C)

Torch Drag Angle 5 - 15°

Travel Speed 4 - 8 in/min

Expected Hardness 62 - 65 HRc

Expected ASTM G65 mass loss 0.08 - 0.12 g



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Vecalloy 700 - Polymet Technical Datasheet