Stainless steel has excellent quality and characteristics, so its application is more and more widely, and worldwide stainless steel production and demand has been a continuous growth trend. As a universal corrosion resistant material, 304 stainless steel sheet can be cold rolled to produce high performance products, which can be used in many fields including food industry equipment, kitchen utensils and electronics industry. Different uses in various fields, the performance requirements of cold rolled stainless steel 304 are not the same, especially when the thickness of the stainless steel strip is small, it is very important to seek its comprehensive cold working performance. By analyzing the effect of rolling and annealing process on its properties and structure, the influence of production process parameters on its structure and properties is studied, which can provide experimental data for field optimization of production and improvement of performance.
The experimental material is 304 stainless steel produced by a factory. Its chemical composition (mass fraction, %) is 0.0528C, 0.5166Si, 0.03P, 1.1983Mn, 0.0016s, 17.016Cr, 8.0061Ni, 0.1989Cu, 0.083Mo, 0.0087Sn. The samples were annealed at different temperatures (1060, 1080 and 1100℃) for different times (2, 5 and 8min). Tensile test was carried out on electronic universal testing machine to measure its strength and calculate n and R values.
The results show that grain size and R value increase with the increase of cold rolling reduction. This is due to the improvement of deformation storage energy, which makes the recrystallization driving force larger, promotes the growth of grain, the result is beneficial to improve the stamping properties of the material. So the deep drawing properties of the material can be improved by increasing the cold rolling reduction rate. With the increase of annealing temperature and the extension of holding time, the grain size increases and the compressive strength ratio decreases, and the grain size is uniform, which is helpful to enhance the deep drawing properties of the material. In order to obtain a higher R value without loss of other properties, the appropriate annealing process is 1100℃×5min in production.