Methods of evaluation welded seams durability for cold cracks formation (Part 1).

The cold crack (chipping off) is the most frequent defect of fusion zone during fusion, which is located in certain distance from the fusion surface. The temperature conditions of these cracks formation and character of their development gives basis to connect the process of their formation with delayed fracture phenomenon.

When developing method of evaluation of susceptibility to chipping off formation Continue reading →

Pores in welded joint (part 1).

According to AWS A3.0 document the porosity is determined as “continuity transgression in the form of hollow space, formed by captured gas in consolidation process”. Thus we have a right to examine pores as certain hollow spaces or gas pockets inside consolidated metal of welded joint. Thanks to characteristic spherical form the pores are considered to be the least dangerous continuity Continue reading →

Welding cracks and their classification.

According to dimensions and influence on metal density are there two categories of cracks (local ruptures): microcracks (their dimensions are comparable to dimensions of crystal lattice parameters; are available almost always in real crystals) and macrocracks which appear in weld joint in the course of welding or use of product (are dangerous defect – reason for structural failure).

Continue reading →

Scroll Up