Corrosion and Failure analysis

Corrosion has been defined in many ways, including “Destruction of metal by chemical or electrochemical reaction with the environment” and “Destruction of materials by means other than straight mechanical”. This process upshot every industry giving rise to significant and continual loss in revenue, equipment and resources.  A huge amount of wastage in metals annually occurs due to corrosion. The well-known form of corrosion is Rusting. Rusting of iron-to-iron oxide is a well-known example of electrochemical corrosion. Metals reacting with oxygen and sulphur are known as electrochemical oxidation.

Corrosion not solitary happens in metals but additionally in many other materials like polymers or ceramics. One of the notable reasons for lower quality of metals or materials is corrosion because of which useful properties like strength, appearance and permeability change to gas or liquid. The main reason for the corrosion is exposure to moisture in the air, but due to exposure to certain substances, this process can be strongly affected.

Corrosion occurs when the surface is exposed because corrosion locally forms a pit or crack, it occurs less uniformly, and extends across a wide area more or less corroding surface. This process is less visible and predictable.

Middle East Testing Services offer periodic testing service through its specialized testing staff and expert which help in preventing corrosion, ensuring the quality check and increasing the life span of metal by identifying signs of fatigue pitting cracking and rusting as well as other forms of damage. Problems like measurement of remaining wall thickness in pipes, tubes, or tanks that may be corroded on the inside surface remain predominantly important issues in the power generation and petrochemical industries.

Middle East Testing Services offer metal investigation i.e., where corrosion has already taken place during operation. This is beneficial to make preventive action for better corrosion resistance.

Testing Methods

1. Salt Spray Test / Salt Fog Test – ASTM B117:

In Middle East Testing Services Test & Research Centre corrosion is detected by Salt Spray Test / Salt Fog – ASTM B117. It is widely used method and internationally recognized method for evaluating coating under highly corrosive marine condition. It also helps in comparing two or more material. Fast way to analyse the corrosion due to chloride chemical and salt water is Salt Spray test. To collect corrosion resistance data from non-coated and coated alloy is the main purpose of Salt Fog/Salt Spray Test. Being oldest “Corrosion Testing” it is widely used and thus it become universal test. In this test, it is possible to test different type of material like painted, bare sacrificial or noble coating.

2. HIC Testing: Hydrogen Induced Cracking Test

Hydrogen Induced Cracking Test is performed to accurately determine and test the hydrogen induced cracking over exposed surface of metal. HIC testing apparatus meet requirements of ASTM / NACE Standard TM0284 and suitable to test material as per requirements of NACE MR0175.

3. Coating Evaluation:

It is widely used in electronic, biomedical and many other industries dealing in metals-based item. It is a treatment which provide corrosion resistance to prevent failure and corrosion, improve reliability, and increase life of the product. Experts with modern and latest technology will provide clear, accurate analyses and solution to client in a wide range of metal industries.

4. Hydrogen Embrittlement:

If steel become brittle and facture due to subsequent diffusion of hydrogen then hydrogen embrittlement method is used. Stress, environment are secondary reason for the diffusion. The main cause for the diffusion in material is change in chemical properties of the metal in which hydrogen is introduced on the surface of a metal and hydrogen atom are individually diffuse through the metal.

5. Sensitization:

When stainless steel is improperly heated, lead to excessive formation of chromium carbides at the grain boundaries resulting in sensitization. Intergranular attack (IGA) and intergranular corrosion (IGC) is a well-known form of corrosion that result in sensitization.

6. Intergranular attack in austenitic stainless steel can be tested by ASTM A262
7. As per client/industry specification

Solution at Middle East Testing Services & RESEARCH CENTRE

Through specialized staff and expert, we provide solution

• To identify the root cause of corrosion
• Comparing and selecting appropriate material
• Estimating life of the product / metal
• Salt Spray ranking assessment
• Electrochemical evaluation of material and coating

Failure analysis is the study of a specific case of component or equipment failure due to corrosion or mechanical characteristics of corrosion.

Which is directed to find the root causes for the failure and how it possibly prevented in the future.  There are few prime motives to conduct a corrosion failure analysis as claimed by international industrial standards.

They are; To find out the mechanism of corrosion in an industrial process and proposing advices and rectify to avoid the recurrence of similar corrosion failure, in some cases failure analysis is done to scrutinize the damage to metallic components after a chemical accident, fire, leakage or environmental pollution and it’s called forensic analysis.