Results of thickness measurements of oxide layer on samples of zirconium alloys E110, E110М, E635 and E635М tested during 432 days in a loop of reactor LWR15 of Institute of atomic research (Rzhezh, Czechia). The experimental was realized in conditions boric-lithium water chemistry mode PWR with surface and volume boiling of the heat-carrier. Results of in-vessel corrosion are considered in comparison to the results received on similar samples in the inactive channel of reactor LWR-15 and in the conditions of an autoclave. The interrelation of radiating hardening and corrosion of alloys type E110 and E635 under an irradiation with evolution of their structurally-phase condition is Discussed.