INFLUENCE OF CORROSION DAMAGE ON CYCLIC LIFE OF BUTT WELDED JOINTS STRENGTHENED BY HIGH-FREQUENCY MECHANICAL PEENING

摘要

In the article, the results of investigation of efficiency of applying the technology of high-frequency mechanical peening for increasing the fatigue resistance characteristics of butt welded joints of steel 15KhSND with a subsequent longterm effect of the environment climatic factors, characteristic for a moderate cold marine climate are given. The effect of given climate was modeled by holding the joints in the salt fog chamber KST-1 at the temperature of (35 ± 2)°C and during spraying the sodium chloride solution for 15 minutes every 45 minutes. The duration of corrosion tests of specimens in the chamber KST-1 was 1200 h. After holding in the chamber KST-1, the metallographic examinations of the surface layer of the weld metal and the metal of heat-affected zone of welded joints in the initial (non-strengthened) state and in the state strengthened by this technology were carried out. The depth and degree of damage by corrosion spots and cavities of surface layers of weld metal and heat-affected zones of welded joints were calculated. The fatigue resistance characteristics of welded joints in the initial (non-strengthened) state and in the state strengthened by high-frequency mechanical peening were experimentally established after effect of a neutral salt fog for 1200 h.