Abstract: Through the austenitic grain display test in different heat corrosive temperature,it states that the key to display a clear boundary of the austenite grain in the hull steel is that: based on fully quenched (cooling medium is dry ice and 100 g/L NaCl solution),the sample is heat eroded in erosion agent (5 g of picric acid + 100 mL cold water + 10 mL detergent +seven drops of hydrogen peroxide) with the constant temperature. At the same time,the heat erosion temperature and time are adjusted appropriately according to the changes in components.