Specimens of armco iron and steels 09GS and 37G2S possessing strongly different load-extension diagrams are studied. The σ = f (δ) curves are divided into regularly alternating periods, i.e., linear, power within the uniform stage, and I, II, III in the lumped stage. Each period is characterized by the yielding parameter (YP), plasticity components (elongation δ_i), initial stress σ_i, and rate of growth/decrease of the stress (∆σ/δ∆)_i. Analysis of the YP is used to compare the periods in differently hardened specimens. It is shown that the combination of these periods is responsible for the standard mechanical properties of the specimens. The values of the YP are used to trace the relation between the ductility and the crack resistance and to show that the stress σ_II and the elongation \( {\updelta}_{\mathrm{l}}^{\mathrm{IIs}} \) at the start of period II of the concentrated stage may be treated as criteria of crack resistance.

对 armco 钢铁 09GS 和 37G2S 的试样进行了研究，这些试样具有明显不同的载荷-延伸图。σ = f (δ) 曲线被分成规则交替的周期，即在均匀阶段中的线性、功率和在集中阶段中的 I、II、III。每个时期的特征在于屈服参数 (YP)、塑性分量（伸长率 δ _i）、初始应力 σ _i和应力增长/减少率 (Δσ/δΔ) _i. YP 的分析用于比较不同硬化试样的周期。结果表明，这些时期的组合决定了试样的标准力学性能。YP 的值用于追踪延展性和抗裂性之间的关系，并表明应力 σ _II和伸长率\( {\updelta}_{\mathrm{l}}^{\mathrm{IIs} } \)在浓缩阶段的第二阶段开始时，可​​以作为抗裂性的标准。