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 →
Possibility of hot cracks formation in welded seam is determined by next factors:
1) Size and character of plastic deformations, formed in metal of welded seam during crystallization;
2) The speed (rate) of increasing these deformations;
3) Deformational capacity of welded seam metal in temperature range of hot Continue reading →
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 →
For each material, tested for tensile tests, this curve has constant slope. This slope is called elastic modulus.
Steel elastic modulus (or Young modulus) under conditions of room temperature is equal approximately to 30000000 pound-force/inch square, and in case of aluminum this parameter is 10500000 pound-force/inch square. As a matter of Continue reading →
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).
