Overview

Power Plant Technology

Power Plant Technology

The power plant technology is an ambitious and challenging engineering discipline. To provide energy for modern industrial nations a never-ending stream of innovations is necessary. Demands on efficiency, environmental compatibility, and longevity of various components are on an all-time high. In particular, wear on utilized components is a great challenge for the power plant technology. In large, modern plants, tremendous forces are at work that must be endured by these components. Depending on the technology (hydraulic energy, coal, wind power, nuclear power plants or gas-fired power plants), there are many other problems caused by wear to be solved. Frequently, these problems include (but are not limited to) abrasion, cavitation caused by water steam, cold welding, high temperature welding, fatigue and hot gas corrosion. Depending on the environment of the energy technology, wear is primarily caused by mechanical, chemical and thermal stress. For engineers, the issue of reliability arises as maintenance cycles can possibly be prolonged. Boriding (boronizing) with Borocoat® is the perfect solution as it is a universally applicable treatment for a large number of components.

Wear in power plants

Control valves steam conditioning valves, desuperheaters, burner nozzles, and metering devices are subject to complex stress levels in connection to high pressure and temperatures. The simultaneous use of heat- and corrosion-resistant steels (e.g. 1.4922, X20CrMoV11-1) and Borocoat® diffusion layers opens up new possibilities that ensure better wear protection even, at high temperatures.

Which materials used in power plants can be borided?

When it comes to dosing systems of coal fired power plants, low-alloyed steels are preferred. Surface layers above 200µm ensure efficient wear protection. Steam conditioning valves are exposed to high temperatures and pressure, making them vulnerable to corrosion and wear. Heat-resistant austenitic and ferrite steels, stainless steels, and superalloys such as Inconel® applied in such a case. To make these materials even more wear protected, BorTec offers appropriate boriding (boronizing) processes. After applying Borocoat® diffusion layers, the desired basic strength of steels can be precisely adjusted by vacuum hardening and tempering.

Borocoat®-diffusion coatings protect against:

  • abrasive wear
  • cavitation
  • cold welding and galling
  • high temperature wear

  • hot gas corrosion
  • fatigue

Properties Borocoat®

  • High hardness of 1400-2800HV depending on the base material
  • High layer hardness also on unalloyed steels
  • Significantly improved adhesion compared to conventional hard material coatings
  • High resistance against abrasive wear
  • High resistance against adhesive wear
  • Good stability at high temperatures
  • Good resistance against meltings of Al and Zn
  • Good behaviour with respect to acids

Detailed information on the properties of the boride layers can be downloaded here.