Corrosion is a natural process through which refined metals are converted into more chemically stable forms such as oxides, hydroxides and/or sulfoxides. Huge amount of metals get wasted annually due to corrosion. Chemical and/or electrochemical reaction with the working environment is the gradual destruction of materials due to corrosion.
The well-known form of corrosion is Rusting. Rusting in iron to iron oxide is a well-known example of electrochemical corrosion. Metals reacting with oxygen and sulfur is known as electrochemical oxidation.
Corrosion not only occur in metals but also on many other materials like polymers or ceramics. The term use for materials is “degradation”.
One of the significant reason for low quality metals or materials is corrosion due to which useful properties like strength, appearance and permeability changes to gas or liquid.
Due to rusting of iron and steel the estimated economic loss is of £700,000,000 every year. The annual direct cost of metallic corrosion worldwide is $2.2 Trillion USD, predominantly due to Steel Corrosion. Large contribution to this cost is by North America of about US is $423 Billion.
The main reason for the corrosion is exposure to moist air, due to exposure to certain substances this process can be strongly affected.
Corrosion occurs when the surface is exposed because corrosion locally form pit or crack, it occur less uniformly, extend across a wide area more or less corroding surface. This process is less visible and predictable.
SIGMA TEST & RESEARCH CENTRE offer periodic testing service through its specialized testing staff and expert which help in preventing corrosion, ensuring the quality check and increasing life span of metal by identifying signs of fatigue pitting cracking and rusting as well as other form of damages. Problems like measurement of remaining wall thickness in pipes, tubes, or tank that may be corroded on the inside surface remains predominantly an important issue in the power generation and petrochemical.
SIGMA TEST & RESEARCH CENTRE offer metal investigation i.e. where corrosion has already taken place during operation. This is beneficial to make preventive action for better corrosion resistance.
In Sigma 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 help in comparing two or more material. Fast way to analyze 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 test” is widely used and thus it became a universal test. In this test, it is possible to test different type of material like painted, bare sacrificial or noble coating.
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.
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.
If steel become brittle and fracture 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 is material and chemical properties of the metal in which hydrogen is introduced on the surface of a metal and hydrogen atom individually diffuse through the metal.
When stainless steel is improperly heated, lead to excessive formation of chromium carbides at the grain boundaries then sensitization occur. Inter-granular attack (IGA) and inter-granular corrosion (IGC) is a well-known form of corrosion that result in sensitization.
Through specialized staff and expert, we provide solution