micro / macro examination

A specimen is etched during macro-etching, and macro-structural analysis is performed at low magnifications. It is a method that is widely used to assess steel goods like billets, bars, blooms, and forgings. For both carbon and low alloy steels, there are many methods to analyze a steel specimen using a graded series of images that demonstrate the occurrence of specific circumstances. Depending on the type of investigation, a variety of different etching reagents may be utilized. Because of differences in chemical composition, manufacturing processes, heat treatment, and many other factors, steels respond differently to etching solutions. 

On polished and etched cross-sections of welded material, macro examinations are also carried out. The weld run sequence, which is important for weld procedure qualifications tests, can be identified throughout the inspection together with other elements. In addition, any flaws found on the sample are examined for compliance with relevant criteria. Among the characteristics seen in this kind of study include slag, pores, a lack of weld penetration, a lack of sidewall fusion, and a poor weld profile. Such flaws are procedurally detectable, either through routine visual inspection or up to 50X magnification. Another common practise is to take a photo of the portion to serve as a permanent record; this is called a photo macrograph.