മെറ്റീരിയലുകളുടെ ഗുണമേന്മ വിലയിരുത്താനുള്ള മാർഗ്ഗങ്ങൾ

DESTRUCTIVE AND NON-DESTRUCTIVE TEST

Destructive Testing is undertaken in order to understand a specimen’s performance or material behaviour, these procedures are carried out to the test specimen’s failure. Its procedure can either follow specific standards or can be tailored to reproduce set service conditions. Destructive testing methods are commonly used for materials characterisation, fabrication validation and failure investigation and can form a key part of engineering critical assessments, which also involves Non-Destructive Testing techniques such as digital radiography.

Types of Destructive Testing

  

·         Aggressive Environment Testing

·         Corrosion Testing

·         Fatigue Testing

·         Fracture and Mechanical Testing

·         Hydrogen Testing

·         Residual Stress Measurement

             

Non-Destructive Testing is a wide group of analysis techniques used in science and technology industry to evaluate the properties of a material, component or system without causing damage. NDT is commonly used in forensic engineering, mechanical engineering, petroleum engineering, electrical engineering, civil engineering etc.

Types of Non-Destructive Testing

•  Visual Inspection Testing
•   Penetrant Testing
•   Magnetic Particle Testing
•   Ultrasonic Testing
•    Radiographic Testing

Visual Inspection Testing

It is the first step in the examination process to inspect a variety of product forms including costing, forgings and machined components and weld elements according to the NDT training and test centre. It is used in maintenance of facilities mean inspection of equipment and structures using either or all of raw human senses such as vision, hearing, touch and smell or any non-specialized inspection equipment.

Penetrant Testing

It is a widely applied and low cost inspection method used to check surface breaking defects in all non-porous materials. The principle of liquid penetrant testing is that the liquid penetrant is drawn into the surface breaking crack by capillary action and excess surface penetrant is then removed; a developer [typically a dry powder] is then applied to the surface, to draw out the penetrant in the crack and produce a surface indication.

 Magnetic Particle Testing

It is utilized to detect defect or  discontinuities at or near the surface in ferromagnetic metals such as iron, steel, nickel, cobalt etc. The principle of the method is that the specimen is magnetised to produce magnetic lines of force, or flux in the material.

Ultrasonic Testing

It is a method of characterizing the thickness or internal structure of a test piece through the use of high frequency sound waves. It can be used for flaw detection/evaluation, dimensional measurements, material characterization, and more. Driven by the pulser, the transducer generates high frequency ultrasonic energy.

Radiographic Testing

It is a Non-Destructive Examination technique that involves the use of either X-Rays or Gamma rays to view the internal structure of a component. In the petrochemical industry, RT is often used to inspect machinery, such as pressure vessels and valves to detect for flaws. It is based on the principle that radiation is absorbed and scattered as it passes through an object.