The sand casting parts testing always includes the appearance, internal quality, and usage quality. Appearance refers to the sand casting parts' surface roughness, surface defects, size deviation, shape deviations, weight bias; Internal quality mainly refers to the intrinsic quality of the sand casting parts chemical composition, physical properties, mechanical properties, microstructure and the existence of the casting within the holes, cracks, inclusions, segregation, etc.; usage quality refers to the sand casting parts can resist corrosion, friction, absorb shock under different conditions.
The hardness of the sand casting parts is an important testing standard.
How to detect sand casting parts hardness? Its hardness directly affects the quality of their processing. In many researches, the casting parts hardness is an important indicator for sand casting parts.
1. Brinell hardness: mainly used to inspect the hardness of sand casting parts, forgings, nonferrous metal parts, hot-rolled and annealed pieces of billet. The measurement range: HB450.
2. Rockwell Hardness: HRA is mainly used for sand casting parts specimens with high hardness. Dimension of the scope HRA> 70. HRC is mainly used for steel parts (such as carbon steel, tool steel, alloy steel, etc.) After quenching or tempering, the hardness testing usually is HRC20 ~ 67.
3. Vickers hardness: this indicator is used to test the hardness of steel sand casting parts It can also be used to determine the carburizing, cyanide, nitrogen and other parts of the hardness of the surface hardening.