Corrosion mesurement techniques

  • Thread starter stats_student
  • Start date
  • Tags
    Corrosion
In summary, corrosion measurement techniques are used to assess the level of corrosion on a material or surface. These techniques include visual inspection, weight loss analysis, electrochemical methods, and non-destructive testing. Each method has its own advantages and limitations, but they all aim to provide accurate and reliable data on the corrosion rate and severity. These techniques are essential for identifying potential corrosion issues and implementing appropriate preventive measures to prolong the lifespan of materials and structures.
  • #1
stats_student
41
0
Hi guys i was wondering if there are methods available which allows one to measure corrosion that occurs in areas of materials where obvious defects exist like holes etc.

Instead of using the conventional methods which measure uniform corrosion?

Thank you in advance.
 
Engineering news on Phys.org
  • #2
There are very crude and very sophisticated methods .

At minimum the corroded area gets cleaned up and visually inspected and plate thickness measured . Quite common practice is to remove sample bolts from any badly corroded area and measure plate thickness through the hole .

There are more sophisticated methods using ultra sound but these are often difficult to use for complex assemblies .

At top end of the scale there is X-ray and radioactive source imaging .
 
  • #3
is there a specific name for these high end techniques? like are the categorized in under some search name?

thanks.
 
  • #4
oh and also could you add an explanation by removing sample bolts from a hole. Is what you are saying is that one places a bolt in a hole then let corrosion take place and then measure the bolt?

thanks again
 
  • #6
stats_student said:
oh and also could you add an explanation by removing sample bolts from a hole. Is what you are saying is that one places a bolt in a hole then let corrosion take place and then measure the bolt?

No - Bolts are removed from areas which are already corroded so as to allow examination of the hole and assessment of plate thickness .

It may sound odd but holes are sometimes deliberately drilled in corroded boiler plates so that thickness of plates can be measured . Hole is then closed again with screwed plug .
 
  • #7
is there a name for the curde measurement technique Nidum?
 
  • #8
stats_student said:
is there a name for the curde measurement technique Nidum?

I can't think of one general name . It comes under things like ships hull inspection , crane inspection , boiler inspection , bridge inspection etc .

Here's a link for bridges : https://www.google.co.uk/search?q=B...-8&oe=utf-8&gws_rd=cr&ei=vG4aVteqOMGsa9-FupgL

One for ships hulls : https://www.google.co.uk/search?q=c...-8&oe=utf-8&gws_rd=cr&ei=-W4aVoXSHciza_bZsegC

And one for boilers : https://www.google.co.uk/search?q=c...iza_bZsegC#q=corrosion+measurement+in+boilers
 
  • #9
Corrosion detection methods have become more sophisticated in all branches of engineering in the last few years . The older cruder methods are being phased out and the more advanced methods are coming into common use .

Note that corrosion measurement is no use unless there is some standard available to decide what level of corrosion is allowable .
 
  • #10
stats_student said:
is there a specific name for these high end techniques? like are the categorized in under some search name?

thanks.
One could look at "localized corrosion monitoring" or "in situ assessment", or "in situ corrosion monitoring" as part of a phrase or in conjunction with corrosion, measurement and/or inspection as key words. One could also look for NDE/NDT or non-destructive evaluation/testing methods.

There are different approaches based on the scale. One may monitor the corrosion environment, e.g., measuring the electrochemical potential, but that requires know about the environment at the local of interest, and for a large system, e.g., air craft, ship, marine structure, nuclear reactor, space craft, there are lots of places to inspect and lots of environments. Looking at hundreds or thousands of rivets or bolts, or other connection for crevice corrosion is time consuming and may be unfeasible. Looking into large structures, e.g., pressure vessels, piping, beams, reinforced concrete structures can be very challenging.

In the case of inspection, one has various tools, e.g., ultrasonics, eddy current, visual, various radiographic (X-ray, gamma-ray, neutron) techniques. The problem with radiography is that the usually one has to place a source and detector on opposite sides of the structure of interest.

Examples of acoustic emission

Monitoring the corroding environment in conjunction with a structural analysis is yet another approach. The objective is to identify the locations most susceptible to corrosion and to monitor specific sites.

One would find a number of articles in Corrosion Journal on in situ assessment or monitoring of pitting or crevice corrosion.
e.g., http://corrosionjournal.org/doi/abs/10.5006/1.3452399

Of course, laboratory conditions (which tend to be more controlled) are more ideal than field conditions.
 

FAQ: Corrosion mesurement techniques

1. What is corrosion measurement?

Corrosion measurement is the process of determining the extent and rate of corrosion on a material or structure. It involves using various techniques and tools to collect data and analyze the corrosion behavior.

2. Why is corrosion measurement important?

Corrosion measurement is important because it allows us to assess the condition of materials and structures, identify potential corrosion issues, and make informed decisions about maintenance and repair strategies. It also helps us understand the effectiveness of corrosion prevention measures.

3. What are the most commonly used corrosion measurement techniques?

The most commonly used corrosion measurement techniques include weight loss analysis, electrochemical methods (e.g. corrosion potential, polarization resistance), corrosion coupons, and non-destructive testing methods (e.g. ultrasonic testing, eddy current testing).

4. How do you choose the most appropriate corrosion measurement technique?

The choice of corrosion measurement technique depends on several factors such as the type of material, the environment, the expected corrosion rate, and the desired level of accuracy. It is important to consult with corrosion experts and consider the advantages and limitations of each technique before selecting the most suitable one.

5. Can corrosion measurement techniques predict the future behavior of materials?

While corrosion measurement techniques can provide valuable information about the current condition of materials and structures, they cannot accurately predict their future behavior. Corrosion is a complex process influenced by many factors, and it is difficult to accurately predict its behavior over time. However, these techniques can help us identify potential corrosion issues and take appropriate measures to prevent or mitigate them.

Back
Top