Grain Flow Analysis

The inner structure of a metal is made up of individual crystalline areas known as 'grains'. The material composition and manufacturing procedures (e. g. forging, casting or additive manufacturing) will influence the structure, size and orientation of these grains. The grain flow refers to the directional orientation of metal grains and any inclusions that have been deformed during rolling or forging. During forging, the brittle impurities of the metal are broken and distributed in a granular or chain shape along the main elongation direction of the metal, while the plastic impurities are distributed in a band along the main elongation direction with the metal deformation. Grain flow is one of the major benefits by the use of forgings. The metal's mechanical properties associated with retarding crack propagation depend on the grain flow and the direction of the moving crack. Optimum alignment between the crack propagation direction and the grain flow can significantly improve the properties such as fatigue strength, impact toughness and ductility.

Grain flow analysis is used to observe the grain flow distribution, and to check whether there are some phenomena such as irregular flow, folding, turbulence, crossing flow and so on.

Test Method

STEMart conducts grain flow analysis by etching the surface of the test material with specific acid (nitric acid or sulfuric acid solution) to reveal the pattern of grain flow.

For more information about our grain size analysis services, please contact us.