Expanite® Surface Hardening
vs. tungsten carbide coating

Expanite is widely replacing coatings like tungsten carbide coatings in a variety of demanding applications.

For more than 70 years, coatings, in their various forms, have been “the standard” to improve resistance towards wear, impact and corrosion for stainless steel components in a great variety of industries, including food & beverage processing, oil & gas, aerospace, transportation, industrial and consumer products.

However, in recent years several performance limitations associated with coatings have driven the engineering community to seek better coating materials, as well as more cost-effective methods to apply them.

Among the most promising alternatives is the patented Expanite hardening technology. Recently, one of the world’s leading manufacturers of precision nozzles and nozzle systems has converted from tungsten carbide coatings to Expanite surface hardening after experiencing quality issues with the coating cracking off. In cooperation with Expanite, they found a case hardening solution that made the surface of the nozzles resistant against chipping, cracking, delamination, etc.

The specific customer performed field tests over a period of several months where the results from Expanite-hardened nozzles showed significant increased lifetime without any premature failure. Based on the test results, the conversion to Expanite hardening was implemented. Expanite’s customer made the following statements:

Traditional coatings, such as tungsten carbide coating or PVD/CVD layers, provide a hard outer shell but can suffer from poor adhesion and brittleness. Over time, microcracks can propagate through the coating, eventually leading to delamination, flaking, or failure under cyclic loading. Once the coating fails, the exposed stainless steel underneath becomes susceptible to galling and corrosion, resulting in costly downtime and maintenance.

In contrast, Expanite’s surface hardening and heat treatment process fundamentally changes the properties of the stainless steel itself rather than adding an external layer. This case hardening solution approach creates a gradient of hardness beneath the surface that improve wear resistance, while maintaining the corrosion resistance.

The patented Expanite processes are diffusion-based, meaning it modifies the atomic structure of the steel surface, ensuring that no coating can peel, chip, or crack.

The result is an improvement in wear, galling, and corrosion resistance for components made from stainless steel and titanium.

The Expanite hardening technology is suitable for several alloys such as AISI 304, 316, and duplex steels, and it offers a direct replacement for tungsten carbide coating in applications that demand durability, precision, and reliability.

From a sustainability standpoint, Expanite offers a cleaner and more resource-efficient solution compared to tungsten carbide coating. The process is non-toxic and eliminates the use of hazardous materials, reduces waste, and minimizes energy consumption — all while delivering longer component lifetime. This aligns perfectly with modern industry goals of lowering environmental impact without compromising performance.

Expanite has successfully implemented its patented surface hardening processes across multiple industries. In addition to nozzle systems, components such as valves, pump parts, cutting tools, and medical equipment benefit from the Expanite treatment. The combination of case hardening depth, smooth surface finish, and maintained corrosion resistance ensures outstanding long-term performance, even in aggressive environments.