Featured Research

from universities, journals, and other organizations

Stainless Steel Corrosion Mystery Solved By UK Researchers

Date:
February 14, 2002
Source:
Imperial College Of Science, Technology And Medicine
Summary:
From cutlery and cooking pans to the inside of a Formula 1 car engine or a huge chemical process plant, stainless steel is all around us. It’s not meant to corrode, but it can, and when it does the results can be disastrous, whether it’s a hole in your dishwasher or a failed industrial plant.

From cutlery and cooking pans to the inside of a Formula 1 car engine or a huge chemical process plant, stainless steel is all around us. It’s not meant to corrode, but it can, and when it does the results can be disastrous, whether it’s a hole in your dishwasher or a failed industrial plant.

Unlike rusting, stainless steel corrosion is highly localised and apparently random. Tiny holes called pits can drill through a substantial thickness of steel in a relatively short time. The pits can cause leaks or act as points from which cracks initiate, similar to the type of defect caused by scoring glass before breaking it, and can cause some of the most catastrophic industrial accidents known.

Why stainless steel fails has long been a mystery, but today with the publication of research in the journal Nature, British researchers claim to have solved it.

‘Stainlessness’ is created by alloying iron with chromium. As the steel ingot cools after it has been made, tiny sulphur-rich impurity particles, about 10 millionths of a metre in diameter, solidify at a lower temperature than the steel, remaining molten for a time after the metal has solidified.

Using an advanced new microscope the team from Imperial College and University College London found a region around these impurity particles that has significantly less chromium than the rest of the steel. During cooling of the steel the impurity particles ‘suck’ chromium out of the steel around them, creating a tiny nutshell of steel that is not stainless.

Corrosion of this layer, just one 10 millionth of a metre thick, is the virus that triggers the main attack say scientists Dr Mary Ryan of Imperial College and Professor David Williams of University College London.

“Most of your household appliances contain stainless steel,” said Dr Ryan of the department of materials at Imperial College.

“It’s quick to clean and has an attractive shiny appearance – this cleanability also makes it the material of choice for applications requiring sterile surfaces such as surgical instruments or plants for producing pharmaceuticals.

“Overall it’s used in countless engineering applications and, in general, it has very good resistance and performs well but it is susceptible to this devastating pitting corrosion. Now we’ve worked out the sequence of events that cause it, we know what causes this Achilles heel, and we can use this information to work out how to fix it,” she said.

The authors suggest that altering the conditions under which it is made could cure the problem without using very expensive low sulphur steels. Another alternative is to use heat treatments after the steel is processed, causing chromium to replenish those sites it has been depleted from, they suggest.

Stainless steel was first made in Sheffield, UK, in 1913.

The research was supported by the Engineering and Physical Sciences Research Council (EPSRC).


Story Source:

The above story is based on materials provided by Imperial College Of Science, Technology And Medicine. Note: Materials may be edited for content and length.


Cite This Page:

Imperial College Of Science, Technology And Medicine. "Stainless Steel Corrosion Mystery Solved By UK Researchers." ScienceDaily. ScienceDaily, 14 February 2002. <www.sciencedaily.com/releases/2002/02/020214080414.htm>.
Imperial College Of Science, Technology And Medicine. (2002, February 14). Stainless Steel Corrosion Mystery Solved By UK Researchers. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2002/02/020214080414.htm
Imperial College Of Science, Technology And Medicine. "Stainless Steel Corrosion Mystery Solved By UK Researchers." ScienceDaily. www.sciencedaily.com/releases/2002/02/020214080414.htm (accessed September 2, 2014).

Share This




More Matter & Energy News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins