Relationship of deformation meso- and macrostructures types with the staging of damage accumulation in welded joints of stainless steel under high-cycle fatigue

ABSTRACT

The fatigue fracture mechanism of spot-welded joints of stainless constructional steel at multi-cycle loading condition is studied using the method of digital images correlation. Analysis of deformation meso- and macrostructures was carried out within the framework of the four-stage scheme of deformation and fracture of welded joints identified in the work. Characteristic fields of displacement vectors are presented and quantitative indicators and duration of damage accumulation stages are determined. On the basis of inverse pseudo-images, new types of deformation structures (trickle and cellular hexagonal) have been discovered.

KEYWORDS:

• Fatigue fracture mechanism
• stainless steel
• spot welding connection
• types of deformation structures