Artikel_ITSC_2022_Zhang

Feasibility study of high velocity oxy-fuel (HVOF) sprayed cermet and alloy coatings for geothermal applications

Geothermal is one of the most under-utilized renewable sources due to high investment costs and long develop-ment cycle. A major cost for geothermal operations is drilling, where cost can increase due to increased drilling depth, increase in tripping times, harsher environments, etc. During drilling, Down-the-Hole (DTH) hammers break the rock through repetitive impact and cuttings are removed via a high-velocity stream. The main failure mechanism of hammer parts is found to be erosion and wear. 

To protect drilling equipment, various coating technologies have been applied.

Selection of appropriate coatings should decrease drilling times, due to longer lifecycles. High velocity oxygen fuel (HVOF) spraying is one of the most popular technique to deposit thick coatings. Its lower flame temperature and high speed can result in dense and good adhered coatings. 

 

 

A study discusses the deposition of cermet and alloy coatings using gas and liquid fuelled high velocity fuel spraying technique and their performance in simulated geothermal drilling environment. 

 

  

  

 

The properties of the deposited coatings in terms of microstructure, hardness, and erosion-corrosion resistance have been studied and the performance are compared with selected benchmarking steels used in geothermal drilling.


Based on the findings of this study, recommendations are made for HVOF coatings that can be potentially used in geothermal applications. 


Read a brief summary of the study as PDF.

 



This article is only available in English. It was provided by:

Dieser Artikel ist lediglich in englischer Sprache verfügbar. Er wurde zur Verfügung gestellt von:

TWI Head Office

Granta Park, Great Abington

Cambridge CB21 6AL

United Kingdom

T: +44 (0)1223 899000

Fax: +44 (0)1223 892588

 Ansprechpartner: Dr. Feifei Zhang


Any kind of reproduction and transfer of content (text, image, graphics, etc.) and layout to third parties is prohibited without the written, prior and express permission of the author.

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