T157 Overlays - Production, Attributes and Applications

Introduction to Overlays from Trimay

Five different types of overlays are available from Trimay. They include:

• Chrome
• Complex
• 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

Chrome Overlays

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

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

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.

Borocarbide Overlays

T171 borocarbide overlays are the latest class of overlays from Trimay. This class of products was co-developed by Trimay with the 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.

T157 Overlay from Trimay

Description of the T157 Overlay

The T157 overlay is made of iron-based steel comprising Trimay’s unique proprietary chemical composition. This overlay is designed for operation in heavy wear environments with direct impact probability ranging from mild to moderate. Trimay’s T157 chrome overlay is pegged as the top -performing chromium carbide wear plate available in the market. The overlays is characterized by a smooth surface and additional chromium and manganese enhances the wear resistance of the T157 by 30% compared to that of T156.

T157 is often used to prolong fan life at concrete plants

Attributes of the T157 Overlay

The Rockwell hardness test rating of T157 ranges between 56 and 58 HRc and loses only 0.13 g (+/-0.03) on ASTM G65-04 Procedure A mass loss test. The slick drag coefficient of the T157 overlay, which represents its ability to impede material buildup, is 0.185 and it has up to 30% more lasting power than the T156 overlay from Trimay.

Common Applications of the T157 Overlay

T157 overlay is recognised as the chromium carbide overlay with the best wearing characteristics available on the market. T157 wears longer than Trimay’s T138 and T156 chrome overlays and in certain conditions, its use is deemed better than that of complex or tungsten wear plates such as T161 or T170 from a utility optimization point of view. The common applications of T157 include conveyor and coal handling.

T157 is often used to protect against chain abrasion

Production and Installation of the T157 Overlay

T157 overlay can be used as a wear resistant for most varieties of steel. Trimay’s proprietary Submerged Arc Bulk Overlay Welding Process is used for overlaying a T157 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. This type of chrome overlay 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 T157 overlay material using carbon arc gouging. T157 overlays are non-machinable and based on requirement, can be surface-finished EDM or grinding. Fillet or plug welding are the common methods for installing a T157 wear plate and it can be fabricated or bolted with inserts for installation. The weld seams in the wear plate should be overlaid with TWP57w or TWP61w weld wires to ensure uniform wear.

About Trimay

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.