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Description of the method

The WIT method is a non-destructive method of determining the state of materials and the limit numerical values of their mechanical indices based on the determined damping coefficient and hardness.
The WIT method uses the relationship between the hardness of steel and all of its other mechanical indicators. As a result of experimental research and experience in the energy, chemical and petrochemical industries, a relationship was found between these properties. Correct correlation of mechanical indicators and hardness of the tested material occurs only when the structure of the material tested is correct.
The fulfillment of this condition is determined by the numerical value WIT (Intensity Suppression Factor), associated with hardness, constituting the essence of the method - this is the criterion of brittleness or WIT criterion. 
If the material fulfills the criterion of brittleness then it is possible to determine numerical values of mechanical indicators in non-destructive way. This is a guarantee that a given steel is not susceptible to brittle cracks, which means that the crack, if it does occur, will not spread rapidly.

History

The main creator of the method is late PhD, Eng. Józef Stefanowicz, who over 40 years headed the team of people in the Materials Research Department of WITEX SA, created the basis of this method, determined on the basis of research and experience within the characteristics of materials exposed to brittle fracture, operated at elevated temperatures (energy, petrochemical industry), exposed to chemically active compounds (chemical, petrochemical industry).

Area of application

The method is applicable to testing, both new and being operated components.

Tests cover such elements as:

• high-temperature pipelines
• drums, screen tubes, headers
• reactors
• stoves
• other elements working at elevated temperatures and increased pressure

The advantages of the method:

• Quick and non-destructive way to determine the numerical values of mechanical indicators: Rm, Re, Rz, U
• ffective detection of dangerous, pre-failure conditions of devices
• Effective detection of degradation processes in the material structure as a result of high temperatures and stresses.
• Consideration of many factors affecting the strength properties of materials
• Development of boundary characteristics of mechanical indicators for materials typically used in power engineering
• Determining the service life of operating devices through periodic control
• Large savings resulting from an in-depth analysis of the condition of materials (no early replacement of expensive items).
• WIT is a method that, combined with classical NDT tests, allows to assess the state of many important elements of boilers: steam pipelines, headers, collectors, superheaters, etc.