Positive Effects
Improve processing performance: Pickling can remove the oxide layer or rust on the surface of ASTM A606 - 4, making the surface smoother. This is conducive to subsequent processing such as polishing, painting, and welding, and can avoid the negative impact of the oxide film on the processing performance, thereby indirectly ensuring the long - term mechanical properties of the material during use.
Negative Effects
Cause hydrogen embrittlement: During the pickling process, hydrogen will diffuse into the matrix of ASTM A606 - 4 and accumulate at impurities or pores, resulting in increased internal stress, reduced plasticity, and increased brittleness. This will reduce the toughness and fatigue resistance of the material, affecting its long - term mechanical properties.
Lead to over - pickling: If the acid solution temperature is too high, the pickling time is too long, or the acid solution concentration is too high, over - pickling will occur. The surface of ASTM A606 - 4 will become rough and dark in color. In severe cases, there will be round holes - pinholes with a certain depth. This will damage the surface integrity of the material, reduce the strength and wear - resistance of the surface, and have a negative impact on the long - term mechanical properties.
Change surface roughness: Pickling will change the surface roughness of ASTM A606 - 4. Excessive surface roughness may affect the fatigue performance of the material, while too low surface roughness may affect the fit with other components, thereby indirectly affecting the long - term use performance of the material.
