The article contains information concerning a new generation steel designated as PB2 (X13CrMoCoVNbNB9-2-1) intended for the operation in power boilers of fresh steam supercritical parameters. The article presents the results of tests on the effect of welding thermal cycles on the structure, toughness and hardness of the simulated HAZ of power engineering PB2 steel as well as the susceptibility of this steel to hot cracking. The tests involved the use of a simulator of thermal-strain cycles. The publication also contains the results of the tests of similar butt joints in PB2 steel pipes subjected to the post-weld heat treatment.