基于复膜金相法的不锈钢构件组织状态无损识别研究

目的 研究在不破坏电力工业用不锈钢构件的前提下应用复膜金相法对其组织状态进行无损识别。方法提出了一种基于复膜金相法的电力工业用不锈钢构件组织状态无损识别方法。使用便携式磨抛设备现场处理不锈钢构件表面，然后在构件的抛光表面用树脂模具构造原位电解池；注入饱和草酸溶液后，通过便携式直流电源对构件进行腐蚀，清洗吹干后，在腐蚀后的表面通过AC膜制备复膜金相，然后将复膜放置到显微镜下进行显微组织观察。结果 试验结果表明，铸态不锈钢中的组织为原始凝固状态，晶内存在明显的二次枝晶臂形态，而锻态不锈钢为多边形等轴晶组织，且晶内存在大量的孪晶组织。SEM、EDS能谱分析和维氏硬度分析结果表明，铸态不锈钢组织在枝晶间存在明显的Mn、Cr元素偏析，枝晶间凝固偏析会造成枝晶内部和枝晶间性能不均匀；锻态不锈钢平均硬度为202.9HV，高于铸态不锈钢的平均硬度（174.3HV），且锻态不锈钢的硬度分布更均匀。不锈钢构件组织和性能的均匀性会影响其服役性能。结论 提出的基于复膜金相法的电力不锈钢构件组织状态无损识别方法可以为电力工业提供一种安全、高效的构件检测手段。通过复膜金相法可以对电网设备中的不锈钢构件进行无损鉴定...

Nondestructive Identification and Research of Stainless Steel Component Microstructures Based on Replica Metallography Method

The work aims to study how to achieve non-destructive identification of stainless steel components in the power industry without damaging their structure. A non-destructive identification method for organization status of stainless steel components in the power industry based on the metallurgical replication method was proposed. A portable grinding and polishing device was used to process the surface of stainless steel components on site, and then an in-situ electrolytic cell was constructed on the polished surface of the component with a resin mold. After injecting a saturated oxalic acid solution, corrosion was carried out with a portable direct current power source, and then a replica metallography was prepared from the cleaned and dried corroded surface with an AC film. The replica was then removed and placed under a microscope to obverse the microstructure. Experimental results showed that the cast stainless steel was in its original solidification state, and there was an obvious secondary dendrite arm morphology inside the crystal. Meanwhile, SEM, EDS spectrum analysis, and Vickers hardness analysis showed that there was obvious Mn and Cr element segregation between dendrites in cast stainless steel, and the solidification segregation between dendrites could cause uneven performance inside and between dendrites. The average hardness of forged stainless steel was 202.9HV, higher than the 174.3HV of cast stainless steel, and the hardness distribution of forged stainless steel was more uniform. Therefore, the uniformity of the structure and performance of stainless steel components affected their service performance. The proposed non-destructive identification method based on metallurgical replication for stainless steel components in the power industry can provide a safe and efficient component detection method for the power industry. Through the metallurgical replication method, stainless steel components in the power grid equipment can be identified non-destructively.