Some Mechanical Characteristics of Structural Steels of Cooling Systems of Continuous Operation

The results of experimental research of low temperatures influence on mechanical characteristics of structural steels of long-term operation in chemically aggressive environments of cooling systems are presented. It is shown that such characteristics of pipe steel as impact toughness (according to Charpy), critical coefficient of stress intensity (fracture toughness), critical crack opening, and microscopic resistance significantly decrease when temperature changes from 20 to -50°C, which indicates a significant decrease in crack resistance of the material. It has been established that the indices of ductile-plastic properties – yield strength, relative longitudinal and transverse deformations decrease sharply in the process of prolonged (up to 30 years) operation of pipe steel. At the same time, intensive flooding of metal takes place.