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目的研究HBF4(氟硼酸)对1Cr18Ni9Ti奥氏体不锈钢腐蚀行为的影响规律,为工业酸洗除垢提供腐蚀方面的依据。方法采用旋转挂片法、金相显微镜与扫描电子显微镜观察等手段研究HBF4对1Cr18Ni9Ti奥氏体不锈钢腐蚀行为的影响,并对其除垢性能进行评价。结果 HBF4的水解产物HF溶解了1Cr18Ni9Ti奥氏体不锈钢表面的钝化膜,造成金属表面发生剧烈腐蚀。金相与SEM照片及能谱分析显示,HBF4对金属表面的破坏以不均匀的全面腐蚀为主,具有非常明显的点蚀特征。旋转挂片法实验表明,1Cr18Ni9Ti奥氏体不锈钢腐蚀速率随时间的延长而逐渐降低,并趋于稳定;升高温度与增加流速都会使腐蚀速率加快,不同的是流速对腐蚀速率的影响表现出了明显的线性关系。除垢试验显示,HBF4对碳酸盐水垢有较好的去除效果,除垢率可以达到97%以上。结论选用HBF4去除水垢时,只有严格控制好清洗工艺参数,才能降低其对基材的腐蚀的影响,延长设备的使用寿命。
Aim To study the influence of HBF4 (fluoroboric acid) on the corrosion behavior of 1Cr18Ni9Ti austenitic stainless steel and provide basis for the industrial pickling descaling. Methods The effects of HBF4 on the corrosion behavior of 1Cr18Ni9Ti austenitic stainless steel were studied by rotating coupon method, metallographic microscope and scanning electron microscopy. The descaling performance was also evaluated. Results HF, the hydrolyzate of HBF4, dissolved the passive film on the surface of 1Cr18Ni9Ti austenitic stainless steel, causing severe corrosion on the metal surface. Metallographic and SEM photographs and energy spectrum analysis showed that the destruction of HBF4 on the metal surface is mainly due to the non-uniform and complete corrosion, with a very obvious pitting corrosion. Rotational coupon method experiments show that the corrosion rate of 1Cr18Ni9Ti austenitic stainless steel gradually decreases with time and tends to be stable; increasing the temperature and increasing the flow rate will accelerate the corrosion rate, the difference is that the flow rate of the corrosion rate showed The obvious linear relationship. The descaling test shows that HBF4 has a good removal effect on carbonate scale, and the descaling rate can reach over 97%. Conclusion When using HBF4 to remove scale, only strict control of cleaning process parameters can reduce the impact of corrosion on the substrate and prolong the service life of the equipment.