The technological properties of reinforcing bars include many items. Different requirements can be put forward according to the characteristics of different products, such as bending and reverse bending (reverse bending) tests for ordinary reinforcing bars, and repeated bending, torsion and winding tests for some prestressing steel bars.

　　所有这些试验的形式不同程度地模拟了材料在实际使用时可能涉及的工艺加工方式，如普通钢筋需要弯钩或弯曲成型，预应力钢丝有时需缠绕等，而其目的就是考核材料对这些特定塑性变形的极限承受能力，因而工艺性能也是对材料的塑性要求，且与上述延性（伸长率）要求是相通的，一般来说伸长率大的钢材，其工艺性能也好。

　　All of these tests simulate to varying degrees the processing methods that may be involved in the actual use of materials, such as bending or bending of ordinary steel bars, winding of prestressing steel wires, etc. The purpose of these tests is to assess the material's ultimate bearing capacity for these specific plastic deformation, so the process performance is also a plastic requirement of materials, and is in line with the ductility (extension) mentioned above. Length) Requirements are common. Generally speaking, steel with high elongation has good technological properties.

　　然而与拉伸时的单向受力状态相比，工艺性能试验的受力状态就复杂得多，试样变形类型与大小则各向（轴向、径向）不同，钢材的组织结构、晶粒大小、有害残余元素含量特别是内部和表面任何影响连续变形的缺陷如裂纹、夹杂等都可能影响和导致试验不通过。所以在某种意义上，对于考核钢材的质量，可以说工艺性能试验更为严格。

　　However, compared with the unidirectional stress state under tension, the stress state of the process performance test is much more complex. The deformation type of the specimen is different from that of the specimen in all directions (axial and radial). The structure, grain size, harmful residual element content of the steel, especially any defect, such as cracks and inclusions, which affect the continuous deformation of the internal and surface, may affect and lead to the failure of the test. Therefore, in a sense, for the assessment of steel quality, it can be said that the process performance test is more stringent.

　　另外钢筋的反向弯曲试验本质上是一项应变时效敏感性试验这是由于钢水中一般都含有一定数量的游离氮（N），也称残余氮，含量过高时，可导致钢材经塑性变形后在室温下脆化。

　　In addition, the reverse bending test of steel bar is essentially a strain aging sensitivity test, which is due to a certain amount of free nitrogen (N), also known as residual nitrogen, in molten steel. When the content is too high, the steel can be brittle at room temperature after plastic deformation.

　　由于钢筋常常需弯曲成型以后使用，已经产生了塑性变形，如果材性变脆，结构就不能承受使钢筋再产生塑性变形的外加荷载（如地震），所以目前国内外都将反弯试验作为一项重要技术要求列入钢筋标准，同时对钢的氮含量予以限制（不超过0.012%）。

　　Because steel bars often need to be used after bending forming, plastic deformation has been produced. If the material is brittle, the structure can not bear the additional load (such as earthquake) which makes the steel bars plastic deformation again. At present, the bending test is included in the steel bar standard as an important technical requirement at home and abroad, and the nitrogen content of the steel is limited (no more than 0.012%).

　　研究表明，用于钢的微合金化的一些元素如钒、钛、铌等，特别是钒与氮有极好的亲和力，钢中加入钒可有效结合自由氮，钒与氮的结合还能进一步增强钒对钢的强化效果，因此有些标准也注明“如果有足够的与氮结合的元素存在氮含量可以高出标准规定”。

　　The results show that some elements used in steel microalloying, such as vanadium, titanium, niobium and so on, especially vanadium and nitrogen have excellent affinity. The addition of vanadium into steel can effectively combine free nitrogen, and the combination of vanadium and nitrogen can further enhance the strengthening effect of vanadium on steel. Therefore, some standards also indicate that "if there are enough elements that combine with nitrogen, the nitrogen content can be higher than the standard requirements".