建筑用钢筋一般多是用碳素钢或低合金钢轧制成的。所谓碳素钢,它的化学成分是以铁和碳为主,还有少量锰、硅、硫和磷等元素。低合金钢和碳素钢不同的地方是,锰和硅的含量上有所增加,有的合金钢还加入了 Most of the steel used in construction is rolled from carbon steel or low alloy steel. The so-called carbon steel, its chemical composition is mainly iron and carbon, there are a small amount of manganese, silicon, sulfur and phosphorus and other elements. The difference between low alloy steel and carbon steel is that the content of manganese and silicon has increased, and some alloy steels have also been added.