Month: May 2022

3 steps to begin experiments…aka…I am lost in this lab!

 All the students in the first few days of research are faced with the dilemma of the right time and way to begin experimentation.


There are as many ways and thought processes to do so as there are people. I will share my learnings here.

The problem is that the literature review tends to become so vast that it is difficult to decide what the exact problem is.

1. The best way is to NOT WAIT for the literature review to get over. Begin with the experiments simultaneously. Gain experience on as many new techniques as possible.

2. Start with that research paper which will most likely form the basis of your work. Attempt to reproduce the experiments in the paper. Try to see what other experiments can corroborate those results.

3. Select the correct research papers to continue the literature review.

P.S. All the experiments should have a reason for doing them. You should be able to answer the question

‘Why should I do this experiment? What will I learn?’



Corrosion risk planning – 2 – Above ground storage tanks – oil and gas- PART 2

 Above ground storage tanks – PART 2

9.    Splash plate

      • corrosion at welds
      • atmospheric corrosion
      • coating damage, if applicable
      • pitting due to chloride salt deposition in marine environment

10.    Spiral staircase

      • corrosion at welds of individual bars and critical joints to the tank
      • coating damage and delamination
      • cracks near welds
      • uniform corrosion at exposed surface near delamination
      • galvanic corrosion near weld/staircase/tank interface due to dissimilar alloys

11.    Manometer

      • corrosion of screws, nuts, and bolts used for attachment
      • possible moisture penetration in case of cracks due to improper handling

12.    Manhole

      • Internal corrosion due to water either as a moisture or as storage product
      • External coating damage due to moisture penetration, dust, rainfall, UV radiation
      • Coating damage at fixtures and edges
      • galvanic corrosion at nuts and bolts due to dissimilar alloys
      • atmospheric corrosion at area where coating is delaminated
      • galvanic/atmospheric corrosion of and at hinges, corrosion product buildup

13.    Drain valve

      • galvanic corrosion in case of dissimilar metals. If valve is of brass, surrounding steel will corrode
      • pitting in case of stagnated water with chloride salts

14.    Concrete drain

      • moisture ingress in concrete
      • possible corrosion of reinforcements especially if any remain exposed

15.    Main inlet

      • Corrosion at welds
      • Crevice corrosion

16.    Automatic tank gauge

      • corrosion at fixtures

17.    Secondary inlet

      • Corrosion at welds
      • Crevice corrosion

18.     Bund wall

      • Concrete degradation due to moisture ingress.
      • reinforcement corrosion at exposed areas
      • Possible biological contamination in case of stagnant undrained water

19.    Pipe bends

      • internal erosion corrosion at the bends
      • external coating damage
      • atmospheric corrosion at point of coating delamination

20.    Floor plates

      • soil side corrosion
      • Insufficient CP
      • coating damage and locoalized corrosion, if coating is used for underside
      • underdeposit corrosion

21.    Foundation settlement

      • soil side corrosion
      • rain water absorption and migration to tank bottom
      • loosening of soil
      • uneven foundation, tilting of tank, preferential corrosion on one side

22.    Roof

      • External atmospheric corrosion
      • coating damage
      • corrosion at welds
      • localized corrosion at points of stagnation
Would love to hear your experience and comments!

Click here for part 1!

😀Happy learning!😀

Corrosion risk planning – 2 – Above ground storage tanks – oil and gas- PART 1

 Above ground storage tanks

1. Inner walls

      • Coating degradation
      • Corrosion due to water/dissolved oxygen
      • insufficient/damaged cathodic protection system
      • dissolved sacrificial anodes

2. Outer walls/roof

      • Atmospheric corrosion
      • coating degradation due to moisture + UV radiation + temperature
      • Erosion and wear due to wind and dust particles
      • biological growth at the bottom areas near soil
      • soil corrosion near the bottom

3. Pipes

      • Atmospheric corrosion
      • Coating degradation
      • mechanical failure
      • internal corrosion due to water/dissolved oxygen
      • crevice corrosion in areas facing away from atmosphere
      • corrosion at welds and joints
      • microbial corrosion at 6 o’ clock positions
      • erosion corrosion at bends

4. Railing

      • Coating degradation
      • Wrong coating selection based on pure aesthetics
      • coating damage at joints and bends
      • corrosion at welds in the railing
      • crevice corrosion at fixtures
      • pitting corrosion

5. Breather valve

      • uniform corrosion/pitting depending on whether it is made up of carbon steel/stainless steel
      • Galvanic couple at the joining/welding point of valve to roof
      • corrosion after damage of galvanized layer

6. Spray nozzle

      • Crevice corrosion at orifices
      • clogging
      • erosion and mechanical damage at orifices and bends
      • crevice corrosion at fixtures

7. Manhole

      • corrosion at edges of cover
      • galvanic corrosion at contact points with neighbouring parts
      • pitting due to chloride ion contact
      • crevice corrosion at fixtures
      • pitting corrosion at welds

8. Lagging

      • pitting due to chloride ion contact
      • crevice corrosion at overlapping joints
      • water seepage at insufficiently bonded overlaps

Click here for part 2!

Electrochemical testing – 1 – Potentiostat

explanation

Potentiostat is an instrument to measure as well as apply potential and current.

It includes a voltmeter and an ammeter. The voltmeter may also be called an electrometer.

It is connected between the working and the reference electrode.

Its main function is to measure the potential of the working electrode.

It is a crucial component because all the experiments require an accurate measurement of the potential to determine their further potential or current variation.

Check out the video for a detailed explanation!

Click here –> https://corrospective.com
😀Happy learning!😀

3 Stages of the beginning of your PhD…aka…OMG what the H am I doing here?

PhD is not a goal, PhD is a journey, and a mighty transformative one at that. That it has different stages is a known fact. However, just the beginning of the PhD has different sub-stages.



The pre-beginning

the admit and preparation to leave

There is fear of the unknown as well as the excited anticipation of new places and people. Specifically in case of Indian students, the flurry of bag packing is accompanied with homemade pickles and snacks.


The beginning

orientation and settling in

The students at this point in time are faced with a bit of anxiety and struggle while searching for accommodation (for overseas universities). There is the factor of being so far away from the family for the first time. Then there also is the undercurrent of being able to manage finances and household chores. A very busy phase indeed.


The post-beginning

where the students settle into their research groups and begin the literature review.

Some may also begin small experiments. There is the enthusiasm of learning a new topic. I remember this being a relatively light phase when the focus was more on learning about not just the academics but also the country and the city.


OR Watch the video here!


Isocorrosion chart snapshot

 concept

  • Isocorrosion chart

Use

  • Estimate corrosion rates for an alloy
  • Select an alloy for a particular application with specific parameters

Definition

  • A plot of temperature versus electrolyte concentration, with lines depicting combination where similar corrosion rates are found

example

how to use it?
  • An application needs a temperature and concentration as depicted by point 1 in the image above.
  • We can plot it on the isocorrosion chart for that alloy and estimate the corrosion rate.
  • The design of the component and corrosion allowance can be decided accordingly.
  • A method to determine the suitability of the alloy for an application and electrolyte-temperature combination.

Video below for practical demo of the use of the chart!

Dive Deeper: Tips to begin experiments

Do you like to solve quizzes?

😀Happy learning!😀

Corrosion risk planning – 1 – Lead acid battery

Corrosion is a quality, environment, and safety issue. Hence, it has to come under the cope of integrated management system audits

However at the moment, it is more or less considered a quality issue.

As such, the general tendency is to solve corrosion issues as they come.

Especially in new inventions, the foresight to look for potential corrosion risk gets lost in the attempt to focus and highlight the amazing qualities of the said inventions.

Hence, I have initiated this series, where I will take a component and point out the potential corrosion and damage risk areas. 

Here goes the first one – lead acid battery cell. (Source:https://opentextbc.ca/chemistry/chapter/17-5-batteries-and-fuel-cells/)

  1.  Protective casing – 
      • effect of temperature + electrolyte + contamination in electrolyte on the polymer
      • crevice corrosion at fixtures
      • mechanical damage during handling leading to voids for moisture ingress and oxygen/electrolyte leakage
  2. Positive terminal –
      • corrosion of the material of terminal due to remnant moisture
      • galvanic corrosion due to terminal and adjoining wires/components
      • crevice corrosion at fixtures
      • effect of anodic potential generated during battery operation – polarization
      • preferential corrosion due to connection with a polymer casing
  3. Negative terminal – 
      • corrosion of the material of terminal due to remnant moisture
      • galvanic corrosion due to terminal and adjoining wires/components
      • crevice corrosion at fixtures
      • effect of cathodic potential generated during battery operation – polarization and cathodic reactions
      • preferential corrosion due to connection with a polymer casing
  4. Cell divider –
      • corrosion of material in the electrolyte
      • degradation of coating on cell divider
      • effect of the generated ions during battery operation on coating
      • mechanical damage during installation
      • friction between divider plate and electrodes
      • for thin polymer coating, possibility of filiform corrosion
  5. Positive electrode –
      • corrosion of material in electrolyte at high temperature
      • cathodic reactions during battery operation
      • excessive localized dissolution due to electrolyte contamination
      • remnant reaction products during charging/discharging leading to localized pH changes and possible galvanic coupling
      • mechanical damage due to friction with adjoining parts (casing/divider)
  6. Negative electrode –
      • corrosion of material in electrolyte at high temperature
      • partially irreversible anodic dissolution
      • excessive localized dissolution due to electrolyte contamination
      • remnant reaction products during charging/discharging leading to localized pH changes and possible galvanic coupling
      • mechanical damage due to friction with adjoining parts (casing/divider)
  7. Dilute H2SO4 –
      • dilution not sufficient for safe handling and disposal
      • contamination due to reaction products
      • concentration modification due to temperature and cathodic reactions
  8. Fixtures for cell construction –
      • Mechanical damage due to friction/installation/handling
      • galvanic coupling with surrounding components
      • localized corrosion due to moisture deposition
      • crevice corrosion

Cathodic protection snapshot

Name of technique

Cathodic protection


Use

  • Prevent corrosion
  • Complement protection given by coatings

Definition

  • A technique where an ionic current towards the structure from the electrolyte is used to counter the corrosion current flowing out of the structure.

CP criteria

  • CP potential of -850 mV vs. CSE
  • An instant off potential of at least -850 mV vs CSE
  • A minimum 100 mV polarization post instant off

CP measurement techniques

  • Soil resistivity
  • CIPS
  • DCVG
  • Line current

Factors affecting CP requirements

  • pH
  • velocity
  • ionic type
  • ionic concentration
  • temperature

Issues with CP

  • Stray current corrosion
  • Insufficient CP potential
  • Insufficient CP current
  • Electrical shorting

I will discuss all these with examples in this major course, where you can prepare for the basics for your certification course!

Check out the introductory video for the brand new course and click on the link to access!


Practice your CP knowledge here! Check out Quiz 1!


😀Happy learning!😀