The mechanical properties of steel bar are the most important performance of steel. The mechanical properties include tensile properties, impact properties and fatigue properties. Today let's take a look at these performance aspects in detail.

　　1、拉伸性能反映建筑钢材拉伸性能的指标，包括屈服强度、抗拉强度和伸长率。屈服强度是结构设计中钢材强度的取值依据。

　　1. Tensile properties reflect the tensile properties of building steel, including yield strength, tensile strength and elongation. Yield strength is the basis of steel strength in structural design.

　　2、冲击性能是指钢材抵抗冲击荷载的能力。钢的化学成分及冶炼、加工质量都对冲击性能有明显的影响。除此以外，钢的冲击性能受温度的影响较大，冲击性能随温度的下降而减小；当降到一定温度范围时，冲击值急剧下降，从而可使钢材出现脆性断裂，这种性质称为钢的冷脆性，这时的温度称为脆性临界温度。脆性临界温度的数值愈低，钢材的低温冲击性能愈好。所以，在负温下使用的结构，应当选用脆性临界温度较使用温度低的钢材。

　　2. Impact performance refers to the ability of steel to resist impact load. The chemical composition, smelting and processing quality of the steel have obvious effects on the impact properties. In addition, the impact property of steel is greatly affected by temperature, and the impact property decreases with the decrease of temperature. When the impact value falls to a certain temperature range, the impact value decreases sharply, which can cause brittle fracture of steel. This property is called cold brittleness of steel, and the temperature at this time is called brittle critical temperature. The lower the critical brittle temperature is, the better the low temperature impact property of steel is. Therefore, the steel with lower brittle critical temperature should be selected for the structure used at negative temperature.

　　3、疲劳性能受交变荷载反复作用时，钢材在应力远低于其屈服强度的情况下突然发生脆性断裂破坏的现象，称为疲劳破坏，疲劳破坏是在地应力状态下发生的，所以危害极大。往往造成灾难性的事故，钢材的疲劳极限与其抗拉强度有关，一般抗拉强度高，其疲劳极限也比较高。

　　3. When the fatigue performance is subjected to repeated alternating loads, brittle fracture occurs suddenly when the stress of steel is much lower than its yield strength, which is called fatigue failure. Fatigue failure occurs under the condition of in-situ stress, so it is harmful. It often causes disastrous accidents. The fatigue limit of steel is related to its tensile strength. Generally, the tensile strength is high and its fatigue limit is relatively high.

　　以上就是关于钢筋力学性能的相关解说，后期我们会将供应性能方面的知识进行讲解，有想要了解的人士可以多多关注一下:http://www.jzqgc.com/

　　These are the explanations about the mechanical properties of reinforcing bars. Later, we will explain the knowledge of supply performance. Those who want to know can pay more attention to it: http://www.jzqgc.com./