**Abstract**

The assessment of suitability for further service of the basic material and circumferential welded joints of primary steam pipelines made of 14MoV6-3 steel was made based on the determined characteristics of their mechanical properties and structure. The tests were carried out on materials after service significantly exceeding the design time and 200,000 h. The mechanical properties with respect to the determined class of structure for the basic and welded joint material were compared to the determined class of damage in accordance with the Institute for Ferrous Metallurgy's own classification of the condition of materials after service under creep conditions. The residual life and disposable residual life were determined based on short-term creep tests and referred to the class of existing structure and the class of damage. The assessment of the suitability of the basic and circumferential welded joint material for further service was made.

**Keywords:** creep, welded joint, Cr-Mo-V steel, microstructure, residual life
