Physical and Mechanical Aspects of Corrosion Damage of Distribution Gas Pipelines After Long-Term Operation

The fractographic analysis of the corrosion damage of the pipe surface of the distribution gas pipeline after 40 and 56 years of operation is performed. The mechanisms of formation of corrosion pits, laminations, and deep crack-like defects are systematized. On the basis of laboratory studies, which simulate operation conditions of a distribution gas pipeline in corrosive medium, the basic regularities in general corrosion of steel St. 3 in neutral chloride electrolytes are determined, depending on the value of the current density and chemical composition of the medium.     

Effect of laser irradiation on the magnetic properties of an amorphous Fe<Subscript>73.7</Subscript>Nb<Subscript>2.4</Subscript>Cu<Subscript>1.0</Subscript>Si<Subscript>15.5</Subscript>B<Subscript>7.4</Subscript> alloy

This paper presents an experimental study of the effect of laser irradiation on the magnetic properties of an amorphous Fe_73.7Nb_2.4Cu_1.0Si_15.5B_7.4 alloy. We have measured its magnetic susceptibility and paramagnetic Curie temperature and assessed the response of the key magnetic parameters of the material to laser irradiation. The results of magnetic measurements are analyzed in conjunction with X-ray diffraction data.     

Laser induced structure transformation in Co70Fe3Mn3.5Mo1.5B11Si11 amorphous alloy

Laser induced structure changes in amorphous Co₇₀Fe₃Mn_3.5Mo_1.5B₁₁Si₁₁ alloy have been studied by means of X-ray diffraction and magnetic properties measurements. Both three types of structural relaxations and a starting stage of crystallization process are considered as main characteristics of structure transformation upon laser treatment. Results of investigation of this amorphous alloy at different parameters of laser irradiation have shown that this alloy becomes partly crystalline after irradiation with laser pulse fluence of about 1.8 J/mm² and pulse duration τ = 2 × 10^?5 sec. Increasing of laser pulse fluence above 2.0 J/mm² leads to the destruction of ribbon, due to intensive evaporation.