CORROSION REAGENT FOR DETECTING STEEL MACROSTRUCTURE AND DEFECT, AND DETECTION METHOD

摘要

A corrosion reagent for detecting steel macrostructure and defects, and a detection method; the corrosion reagent is divided into three sub-reagents in order of use, a first sub-reagent comprising 5%-10% H2SO4, 20%-25% HNO3, and 65%-75% H2O, a second sub-reagent comprising 25%-35% HNO3 and 65%-75% H2O, and a third sub-reagent comprising 3%-5% HNO3 and 95%-97% H2O. The detection method comprises the following steps: pretreatment; corroding with the first sub-reagent for 20-30 minutes; corroding with the second sub-reagent for 10-20 minutes; corroding with the third sub-reagent for 3-5 minutes; and scanning and imaging. The method enables the metallurgical defects and microstructure of a steel ingot to be clearly shown without heat erosion, and has low requirements for surface smoothness and flatness of a sample, and is particularly suitable for macrostructure and defect detection for heavy casting and forging.