Exploration & Production

Corrosion basics: High-temperature corrosion

ORME feature

By Pierre R. Roberge. Article originally appeared in Materials Performance Magazine


High-temperature corrosion is a form of corrosion that does not require the presence of a liquid electrolyte. In this corrosion mechanism, metals react directly with gaseous atoms in the atmosphere rather than ions in solution. Sometimes, this type of damage is called “dry corrosion” or “scaling.” The first quantitative analysis to oxidation behavior was made in the early 1920s with the postulation of the parabolic-rate theory of oxidation by Tammann and, independently, by Pilling and Bedworth.

Although temperatures greater than approximately 90 or 150 °C are sometimes considered “high temperature” (e.g., for heated oil pipelines), this article is concerned primarily with temperatures greater than the “red-hot range,” primarily 650 °C and greater. 

Alloys often rely upon the oxidation reaction to develop a stable protective scale that resists further corrosion, such as sulfidation, carburization, and other forms of high-temperature attack. In general, the names of the corrosion mechanisms are determined by the dominant corrosion product(s). For example, oxidation (the general term for a variety of reactions) implies oxides, sulfidation indicates sulfides, sulfidation/oxidation indicates a combination of sulfides plus oxides, and carburization indicates carbides.1

Oxidizing environments refer to high-oxygen activities (concentrations) with excess oxygen. Reducing environments are characterized by low-oxygen activities, with no excess oxygen available. Clearly, oxide-scale formation is more limited under such reducing conditions. It is for this reason that reducing industrial environments are generally considered to be more corrosive than the oxidizing variety.

The properties of high-temperature oxide films, such as their thermodynamic stability, ionic-defect structure, and detailed morphology, play a crucial role in determining the oxidation resistance of a metal or alloy in a specific environment. High-temperature corrosion is a widespread problem in various industries, including:

Refining and petrochemical

Power generation (nuclear and fossil fuel)

Aerospace and gas turbine

Heat treating

Mineral and metallurgical processing

Chemical processing

Automotive

Pulp and paper

Waste incineration

Corrosion resistance at high temperatures stems from a combination of two basic factors: thermodynamics, which determines whether a corrosive reaction will proceed, and kinetics, which determines the rate at which the reaction may proceed. The rate of the reaction may be reduced by careful selection of alloying components, such as inclusion of a multivalent metal that can react with a greater number of oxidizing atoms.

The need for a careful study of the properties of a heat-resistant alloy and its behavior in the anticipated environment is of considerable importance in the selection of a suitable alloy for a particular service application. New alloys and non-metallic materials that are continually being made available to industry are making it possible to make better selections and to establish safe working limits within which the material can be expected to give satisfactory performance over a reasonable length of time.

This article was initially published in Materials Performance Magazine.

References

1 R.C. John, “Compilation and Use of Corrosion Data for Alloys in Various High-Temperature Gases,” CORROSION/99, paper no. 73 (Houston, TX: NACE, 1999).

This article is adapted by MP Technical Editor Norm Moriber from Corrosion Basics—An Introduction, Second Edition, Pierre R. Roberge, ed. (Houston, TX: NACE International, 2006), pp. 217-218.

About NACE International - www.nace.org

NACE International, The Worldwide Corrosion Authority, was established in 1943 by eleven corrosion engineers from the pipeline industry as the “National Association of Corrosion Engineers.”

Today, NACE serves nearly 36,000 members in over 130 countries and is recognized globally as the premier authority for corrosion control solutions. The organization offers technical training and certification programs, conferences, industry standards, reports, publications, technical journals, government relations activities and more.

NACE International is headquartered in Houston, Texas, with offices in San Diego, California; Kuala Lumpur, Malaysia; Shanghai, China, Sao Paulo, Brazil and Al-Khobar, Saudi Arabia.

Materials Performance (MP) magazine is the flagship publication of NACE International. Published monthly, MP is the world's largest circulation journal dedicated exclusively to corrosion prevention and control. 

Hits: 1451

‘Liquidity still tight for small upstream EMEA oil firms’

KuwaitFitch Ratings has described the risks faced by the EMEA small oil and gas exploration and production companies, noting that the sustained fall in global oil price has deteriorated the liquidity positions of small upstream companies in the region

Hits: 2006

Read more ...

NIOC and Japan’s Toyo sign MoU to boost production at Salman field

niocIran’s National Iranian Oil Company (NIOC) has signed a Memorandum of Understanding (MoU) with a consortium that includes Japan’s engineering group Toyo to revamp facilities and upgrade gas production at the Salman field in the Gulf

Hits: 1560

Read more ...

Oman achieves progress in developing Bahja-Rima oilfield

OmanOman’s major oil exploration and production company Petroleum Development Oman (PDO) has achieved significant progress in developing the Bahja-Rima cluster oilfield, thus targeting to reach production capacity of 94,000 bpd by 2021

Hits: 1709

Read more ...

Saudi Aramco to invest more than US$300bn in oil and gas over the next decade

AminHNasserSaudi Aramco is to invest more than US$300bn over the coming decade to reinforce its pre-eminent position in oil, maintain its spare oil production capacity, and pursue a large exploration and production programme centring on conventional and unconventional gas resources, said Amin H. Nasser, the oil giant’s president and CEO in a speech to the World Petroleum Congress in Istanbul

Nasser stressed that long term investments are needed to ensure that adequate and affordable supplies of oil and gas are available through the transition to clean energy sources.

“Rising demand for all sources of energy – with oil and gas at the heart of the mix – will be the reality for decades to come,” he said, warning that the long term situation of oil supplies is ‘increasingly worrying.” Growing oil demand, the natural decline of developed oil fields and the loss of around US$1 trillion of investments throughout the downturn will require around 20mn bpd to be offset over the next five years to counter these effects, he said. New discoveries are also on a major downward trend, he noted.

"Investments in smaller increments such as shale oil will just not cut it,” he said.  

Nasser also focused on Saudi Aramco’s plans to leverage innovation and technology to minimise emissions and fulfil the Kingdom’s commitment to the Paris Agreement. 

He highlighted plans to double production of natural gas to 23 Bcf/d over the coming decade, efforts to promote low emissions technologies, the focus on advancing carbon capture, utilisation and storage technologies, and the conversion of crude oil to chemicals. Saudi Aramco will also play an increasing role in the Kingdom’s programme to build an initial renewables capacity of 9.5GW by 2023, he added. 

 

 

Hits: 1587

Alain Charles Publishing, University House, 11-13 Lower Grosvenor Place, London, SW1W 0EX, UK
T: +44 20 7834 7676, F: +44 20 7973 0076, W: www.alaincharles.com

twn Are you sure that you want to switch to desktop version?