Steel forging quality identification can be analyzed from the following aspects:
1. Chemical composition inspection
Generally, chemical composition inspection of forging blanks is not carried out. Its chemical composition is based on the pre-furnace sampling analysis during smelting. However, for important or questionable forgings, some chips can be cut off the forgings and chemical analysis or spectral analysis can be used to check their chemical composition.
2, appearance shape and size inspection
uses visual inspection, sample or scribing methods to check the surface defects, shape errors and size of forgings to determine whether the forgings meet the requirements of the drawing size.
3, macrostructure inspection
Macrostructure inspection, also known as low-magnification inspection, is to use the naked eye or a magnifying glass not greater than 10 times to inspect the macrostructure of the forging surface or section. The main methods include sulfur printing, hot acid leaching, cold acid leaching, and fracture.
4, microstructural inspection
Microstructural inspection, that is, metallographic inspection, is to observe, identify and analyze the microstructural state and distribution of forgings under an optical microscope, which helps to understand the relationship between microstructure and forging performance. In addition to examining the microstructure, metallographic examination can also show segregation and the distribution of some compounds, and can grade grain size and non-metallic inclusions.
05, ultrasonic flaw detection 1 Ultrasonic flaw detection is a non-destructive inspection, which is to check the internal or surface defects of the forging without damaging the forging. In addition to ultrasonic flaw detection, there are also magnetic flaw detection, radiographic flaw detection, etc. Because ultrasonic flaw detection has the advantages of large penetrating power, high sensitivity, simple operation, fast speed, and harmlessness to the human body, it has become the main method for inspecting internal defects of large forgings. 2
