Affect Factors and Processing Attention of Cold-drawn Steel
Cold-drawn steel refers to the process of deformation by pulling the hot-rolled steel strip under normal temperature. With continuous deformation, the cross section of the hot-rolled steel strip is gradually reduced, and the strength, plasticity and surface hardness of the material are improved, as well as size and shape accuracy. Cold-drawn steel has the characteristics of high efficiency, less energy consumption and low cost.
1. Affect Factors
The properties of cold-drawn steel are mainly determined by the chemical composition of raw materials, the metering accuracy of chemical composition content, the deformation temperature, deformation speed, die structure and lubrication of cold drawing process.
1.1 Chemical Composition
The chemical composition of raw materials determines the main chemical elements in the material, which will affect the performance of cold-drawn steel. In general, the purity of raw materials is required in cold-drawn steel production, and alloy elements should also be strictly controlled. The alloy elements have a great influence on the properties of cold-drawn steel, such as the strength of steel, the quenching performance, the hardenability, the tempering stability and the welding ability.
1.2 Deformation Temperature
Deformation temperature affects the performance of cold-drawn steel in two aspects: first, the work hardening coefficient of cold-drawn steel increases with the increase of deformation temperature, and the strength and hardness of steel also increase; second, high deformation temperature can reduce the unevenness and the center crack defect rate in cold-drawn steel.
1.3 Deformation Speed
The deformation speed of cold-drawn steel has a greater influence on the quality of the product, which can be divided into steady speed and variable speed. The steady speed cold-drawing can improve the hardenability of steel, but the hardenability is not good and the surface defects are easy to occur.
1.4 Die Structure
In cold-drawn steel production, the die structure is one of the important factors that determine the quality of the product. The cross section of the die arch should be consistent with that of the cold-drawn steel. The matching force of materials and die should be close to uniform distribution.
1.5 Lubrication
Lubrication has an important influence on the quality of surface and performance of cold-drawn steel product. Different types of lubricants can be used according to the lubrication condition. The lubrication of cold-drawn steel should conform to the requirements of combining lubrication performance, drawing temperature and product drawing tension.
2. Processing Attention of Cold-drawn Steel
2.1 Cold-drawn steel surface should be mechanically cleaned before blasting and paint coating;
2.2 The operation procedure of cold-drawn steel steel should be strictly followed to reduce the possibility of defects caused by improper operation;
2.3 Check the surface of the steel plate before and after cold-drawing, and measure the parameters such as the thickness of the surface and the position accuracy;
2.4 After cold-drawn steel product is formed, it needs to be carried out to minimize the coverage of the original surface of the cold-drawn steel strip, or it can be processed to obtain a certain surface effect;
2.5 While cold-drawn steel is processed, the burr at the end of the secondary gap and the burr at the top of the die must be prevented;
2.6 Attention should be paid to the maintenance of cold-drawn steel equipment. The equipment should be regularly maintained and checked to ensure the smooth production.
In summary, cold-drawn steel production should pay attention to the analysis of the factors affecting the performance of cold-drawn steel, actively take measures to adjust, and ensure the stability of the product quality. Lubricating effect is an effective measure to improve the quality of cold-drawn steel. The careful selection of the lubricant can control and reduce the friction force, reduce stainless steel hardening, Increase product performance, avoid rejects, reduce cost and guarantee the quality of cold-drawn steel products.
