Experimental studies of surface modification of Eurofer samples have been performed with a quasi-stationary plasma accelerator QSPA Kh-50. The heat load on the surface was near the tungsten melting threshold (i.e. about 0.6 MJ/m2). The plasma streams exposures result in modification of steel-based materials and formation of cellular submicron structures in re-solidified layers. Phase characterized by body-centered cubic lattice appeared due to recrystallization of affected material.