前言 20MnSi中强度钢丝是用于中小型预应力构件以代替冷拔低碳钢丝的新钢种。冷拔低碳钢丝在我国预应力结构中应用已有二十多年的历史。由于它取材容易、加工方便、能大最节约钢材在国内得到了广泛的应用。但在使用中也发现它的一些缺点,强度离散性较大、塑性差、易引起构件脆性破 Introduction 20MnSi medium strength steel wire is a new type of steel used for small and medium prestressed components instead of cold drawn low carbon steel wire. Cold-drawn low-carbon steel wire has been used for more than 20 years in our country’s prestressed structure. Because it is easy to use, easy to process, and able to save most steel, it has been widely used in China. However, some disadvantages have also been found in use, such as large dispersion of strength, poor plasticity, and easy to cause brittle fracture of components.