合金化工艺对超低碳钢GA板镀层抗粉化性能及组织的影响

Effect of Galvannealing Process on Powder-Resistance and Microstructure of Galvannealing Coatings of Ultra-Low Carbon Steel Sheets

合金化工艺是决定合金化镀层组织结构的重要因素之一,而镀层组织结构又是决定其性能的重要因素。获得理想镀层组织和性能的合金化工艺的控制是复杂的,需要对退火过程中Fe-Zn合金反应过程的温度和时间进行精确的控制。以三十六种不同的合金化工艺制度系统研究含钛超低碳钢合金化工艺对其镀层组织、镀层铁含量及镀层抗粉化性能的影响。研究结果表明：合金化工艺为510~525℃、15~20 s时,镀层综合性能为最佳（镀层粉化量7~8 mg）,镀层由薄的Г相、绝大部分的δ相和较少量的ζ相组成,其铁含量（质量分数）约8%~10%。

The galvannealing process parameters are some certain factors that determine the microstructures of galvannealing coating,and also the microstructures have an essential effect on the properties of galvannealing coatings.Acquiring the ideal microstructures and properties of galvannealing coatings is quite difficult and complex,so it is needed to accurately control the temperature and duration of Fe-Zn diffusion process.In this work,36 different galvannealing routes varying temperatures and durations are adopted to investigate the effect of galvannealing process on the microstructures,iron content and powder-resistance of galvannealing coatings.The results show that when galvannealing temperature is between 510-520℃ and duration 15-25s,the properties of galvannealing coating reaches the best（approximately of 7-8mg）.Accordingly,the galvannealing coating is composed of a dominant δ phase layer,a thin Г phase layer and ζ phase.The iron content is approximately 8-10 mass %.