Keyword: «impact strength»

THE EFFECT OF SEVERE PLASTIC DEFORMATION TEMPERATURE ON THE CHARACTER OF FRACTURE OF CONSTRUCTIONAL STEEL

Author:

Mariya Borisova

The paper considers the influence of the temperature regime of severe plastic deformation of constructional steel by equal-channel angular pressing on the character of fracture during Charpy impact tests. It is shown that the formation of a more developed fracture surface with splits, pits and micropores corresponds to a higher value of impact strength, i.e., an increase in the ability to absorb mechanical energy under the impact load of the specimens.

Keywords: severe plastic deformation, impact strength, constructional steel, ultrafine grained structure, fractogamm

OPERATIONAL ASSESSMENT OF THE DEGRADATION OF THE PROPERTIES OF MATERIALS OF STRUCTURES OPERATED IN THE CONDITIONS OF YAKUTIA

Authors:

Afanasii Byrnashev,

Aleksandr Ivanov,

Albert Grigorev,

Egor Byrnashev

The paper explores the problems of maintaining the reliability of steel structures used in hazardous industrial facilities. It aims to introduce a new parameter for the rapid assessment of structural changes in the material of critical structures. It developed a method for rapid assessment of structural changes in the material of critical structures using a non-destructive method based on parameters that are sensitive to degradative changes in structure. It establishes a correlation between speed of sound and toughness for given states of the pipe metal, based on which the method was developed. It substantiates the applicability of these parameters to assess the degree of degradation. A method is proposed for estimating the residual service life of metal in a trunk gas pipeline by changing the speed of sound.

Keywords: impact strength, metal degradation, sound speed, limiting state, long-term operation

FINITE ELEMENT MODELING OF STRESS-STRAIN STATE OF SPECIMENS FOR IMPACT BENDING WITH U-SHAPED AND V-SHAPED STRESS CONCENTRATORS

Authors:

Ekaterina Maksimova,

Leonid Prokopev,

Yakov Andreev,

Semen Semenov,

Evgenii Lykin

Determination of impact strength during mechanical impact bending tests is the main practical method for assessing the susceptibility of steel to brittle fracture (GOST 9454-78). The article points out the disadvantages of this test method. Based on finite element modeling, the loading of specimens under impact bending with different types (shapes) of stress concentrator made of structural steel grade St3 was carried out. As a result of the research, a picture of the stress-strain state in the area of stress concentrators was obtained and the edge effect of stress-strain state was shown.

Keywords: finite element method, stress-strain state, impact strength, impact bending, stress concentrators

IMPACT STRENGTH OF WELDED JOINTS OF LOW-ALLOYED COLD-RESISTANT STEELS USED IN THE CONSTRUCTION OF METAL STRUCTURES IN THE NORTH AND THE ARCTIC

Authors:

Mihail Sidorov,

Igor Sannikov,

Sergei Semyonov,

Ryslan Tihonov,

Nikolai Litvincev

The problem of ensuring the reliability and strength of equipment and structures operating at low climatic temperatures is an urgent scientific and technical task today. Ensuring sufficient cold resistance and strength means preventing brittle fracture of structural elements at loads that are significantly lower than the calculated ones. One of these characteristics is impact strength. The paper presents the results of studies of the impact strength of a welded joint of steel 10ХСНД obtained by DC welding and pulsed arc welding.

Keywords: welded joints, impact strength, welding, mechanical testing, low alloy steel