1. Processing process is different
H116: A pure work-hardened condition, the material is used directly after cold rolling or cold drawing without annealing. This process allows aluminum to maintain a high degree of hardness and strength, but there may be residual stresses within.
H321: On the basis of work-hardening, stabilization treatment (such as low-temperature annealing) is added, which can eliminate part of the residual stress and enhance the stability of the material, making it more suitable for subsequent welding or long-term use.
Differences in mechanical properties
H116: The tensile strength is usually between 275~350 MPa, and the hardness is higher, suitable for scenes that require direct load-bearing (e.g. ship decks, container skeletons).
H321: The tensile strength is slightly lower (about 270~320 MPa), but the ductility and fatigue resistance are better, suitable for repeated force or dynamic load components (such as vehicle chassis, welded structural components).
2. Different emphasis on application scenarios
H116: Mainly used for structures that require high strength and do not require complex welding, such as ship hulls, large storage tanks, and bridge supports.
H321: Because of better stability, it is often used in fields that need to maintain performance after welding, such as aircraft fuel tanks, rail transit car bodies, chemical pipelines and so on.
Surface treatment adaptability
Both can improve corrosion resistance through anodizing, but H321 is more stable after welding due to stabilization treatment, and is suitable for marine or humid environments (e.g., marine welded parts, outdoor equipment supports).
