IFMASS10

191

APPLICATION OF NON-DESTRUCTIVE TESTING PROCEDURES FOR

STRUCTURAL INTEGRITY ASSESSMENT

Stevan Kuzmanović

Energoinvest-IMQ, Sarajevo, Bosnia and Herzegovina

Abdulah Koro, Nedžib Njuhović

Energoinvest-IMQ, Sarajevo, Bosnia and Herzegovina

1. INTRODUCTION

Non-destructive testing methods are used for detection of discontinuities, defects and

imperfections in products, primarily in casings, forgings, plates, pipes, and weldments.

In general, these deficiencies can be divided in that developed:

in casting process of row material;

during manufacturing by rolling, forging, cutting, welding;

in exploitation of components and equipments.

Detrimental effects can be avoided or significantly reduced if deficiencies are detected

in an early stage of manufacturing or service. For that, the role of non-destructive testing

(NDT) is of high importance for structural integrity and life of equipment in service.

Basic knowledge about NDT methods and procedures can be found in textboxes and

literatures, including many lectures held in the previous International Fracture Mechanics

Summer Schools (IFMASS). With this in mind, in addition to classification of imper-

fections and defects, state-of-the-art in the improvement of NDT performance in practice

will be presented here, followed by the examples of recent NDT applications.

2. IMPERFECTIONS AND DEFECTS

Most important deficiencies in equipment and their components are imperfections and

defects. Short overview of them can help to follow next text in an easier way.

2.1. Classification of imperfections

In general, imperfections are classified depending on manufacturing process, type of

material, thickness and other

, in steel castings to 50 mm thick, discontinuities

detectable by radiography are grouped in ASTM E446 standard as follows:

•A – gas porosity,

• B – inclusions of slag and sand,

• C – shrinkage cavity,

• D – cold crack,

• E – hot crack,

• F – inserts,

• G – marble air.

Geometrical imperfections in metallic materials, formed in arc melting process, are

classified in EN ISO 6520-1 as follows:

• 100 – cracks,

• 200 – voids,

• 300 – inclusions of solids,