Introduction to Overlays from Trimay
Five different types of overlays are available from Trimay. They include:
- Nano and
- Two types of Tungsten overlays
The wear characteristics of these overlays are different from each other’s but are better than the regular austenitic, hardened or any other type of steel.
Overlay Selection Parameters
Several variables determine the length of wear of an overlay in each application. Therefore, customers opting for Trimay overlays are advised to do so after considering the following parameters:
- The service life expected from a protective overlay
- The level of abrasiveness of the material that will flow through the pipe to be overlaid
- The extent of impact that the overlay will be exposed to
Types of Overlays from Trimay
Due to their strong wear deterrent and impact absorbing nature, chrome overlays find the widest use in industrial applications. Three types of chrome overlays are available from Trimay, namely, T138, T156 and T157. They are well suited for operations in moderate-to-heavy wear environments and can absorb with mild to moderate impact.
Complex overlays are suitable for corrosive, high-temperature environments and are made using a unique blend of carbides bonded in the form of a tight crystalline matrix. The T161 complex overlay can operate in temperatures up to 650°C or 1202°F and has better wear characteristics than the chrome overlays from Trimay. The T161 complex overlay is best suited for heavy wear applications with the direct impact probability ranging from mild to moderate.
Tungsten overlays from Trimay have the toughest wear characteristics among all overlays. They are available in matrix content above and below 50%. The major distinguishing factor for the two types is that the above 50% tungsten overlay is available as a single layer overlay only whereas the below 50% type can be offered up to three layers. Tungsten overlays from Trimay also absorb impact better than the other two types of overlays.
T171* borocarbide overlays are the latest class of overlays from Trimay. This class of products was co-developed by Trimay with an advanced materials company, NanoSteel Company. Nano is a sub-micron borocarbide alloy that displays far superior wear characteristics than tungsten overlays at much less cost. The T171* overlay from Trimay is best suited for heavy-to-extreme wear applications with moderate direct impact.
T170 Overlay from Trimay
Description of the T170 Overlay
The T170 overlay is made of nickel-based steel comprising Trimay’s unique proprietary chemical composition. This overlay is designed for operation in heavy wear environments with direct impact. Trimay’s T170 overlay is one of the top products of the company with extra-ordinary wear and impact resistance. The T171* is an attempt by Trimay to give a more economical match to the T170’s performance, but fails to meet the expectations.
T170 is used to protect key wear points on crusher rolls like the one above
Attributes of the T170 Overlay
The hardness test rating of T170 ranges between 46 and 50 HRc and loses only 0.05 g (±0.03) on ASTM G65-04 Procedure A mass loss test. The Nickel Chrome Iron Matrix (NCIM) of T170 with Macrocrystalline Tungsten Carbide (MTC) and added elements produces a wearable nickel-containing alloy. Moreover, as MTC carbides stay intact during the whole process of overlay application. The finished overlay is highly ductile and can absorb impact and not fracture.
Common Applications of the T170 Overlay
T170 is commonly used in severe wear conditions and areas exposed to direct impact and is highly economical.
T170 withstands impact and can be used to make durable bucket teeth
Production and Installation of the T170 Overlay
The T170 overlay can be used as a wear plate solution for most varieties of steel. Trimay’s proprietary Submerged Arc Bulk Overlay Welding Process is used for overlaying a T170 wear plate. The overlay can be cut and fabricated to different specifications. Forming or rolling is achieved using press brakes while cutting is accomplished through plasma arc or water jet methods, but it cannot be flame cut. Thickness and the position of the weld (on the inner or outer diameter) determine the formability of the overlay. For low-precision applications, it is possible to remove the T170 overlay material using carbon arc gouging. T170 overlays are non-machinable, and based on requirement, can be surface-finished by EDM or grinding. Fillet or plug welding are the common methods for installing a T170 wear plate and it can be fabricated or bolted with inserts for installation. The weld seams in the wear plate should be overlaid with TWP61w weld wires to ensure uniform wear.
Trimay develops and manufactures the highest quality wear overlays for customers seeking to maximize efficiency by extending the life of equipment, parts and pipelines exposed to severe wear conditions. Trimay achieves its high-quality standard through research and development, partner companies and exclusive suppliers, as well as through in- house experimentation and process optimization.
This information has been sourced, reviewed and adapted from materials provided by Trimay Wear Plate Ltd
For more information on this source please visit Trimay Wear Plate.