ON INTERACTION BETWEEN MATERIAL STRENGTH AND THE STRENGTH OF STRUCTURAL ELEMENTS
Based on the analysis of previously obtained experimental data, the authors of the article developed a new methodology for the assessment of structural steels ability to resist embrittling effect of stress concentrators (SC), which manifests itself in the form of loss of the bearing capacity σ<sub>NF</sub> samples with an annular notch. The concept of a reserve of metal strength (break resistance <i>B</i><sub>r</sub>), performs the function of “clearing” local peak surges in SC zone, blocking a possible reduction in the strength of the product. The critical values of break resistance <i>B</i><sub>rb</sub> ≈ 1,6…2,2 on specimens with notch for steels with different levels of strength in the range σ<sub>0,2</sub> ≈ 300...1500 MPa. It is proposed to use the concept of structural alloy suitability for products containing SC with a known exponent <i>B</i><sub>rb</sub>. The criterion of suitability is the structural condition of <i>B</i><sub>r</sub> ≥ <i>B</i><sub>rb</sub>. A characteristic feature of the alloy structural suitability for products with the SC is a monotonic increase in the structural strength of the product (σ<sub>NF</sub>) with increasing strength of the metal σ<sub>0,2</sub>, indicating the absence of the threat of embrittlement of the products available from the SC.