Quantifying Carbide Banding Severity in Tool Steels for Cell Stamping Dies
Quantifying tool steel carbide banding via ASTM E1268 stereology prevents micro-chipping and premature fracture in high-takt battery cell stamping dies.
Microhardness Mapping
Meaning
Metallurgical indentation testing procedure determines the localized hardness variations across a specific metal cross-section using a grid of microscopic indents. Performing microhardness mapping on battery casing stampings reveals work hardening trends and heat-affected zones from laser welding. The boundary of this test is the spacing limit required to prevent adjacent plastic deformation zones from overlapping, which would otherwise invalidate the measurements and lead to erroneous conclusions.
Testing Pattern
Multi-point grids are placed across the weld boundary to measure the transition from the fused metal to the unaffected base material. This map highlights areas that may be susceptible to cracking under vibration. Precise software controls the position of each diamond indentation.
Hardness Profile
High values near the sheared edge of a cell casing indicate localized strain hardening that occurred during the stamping process. These hard regions can be brittle and prone to cracking during subsequent flanging or assembly steps. Softening the metal via localized heating reduces this risk.
Quality Verification
Engineering teams review these spatial profiles to validate that heat treatment or welding parameters are within specified boundaries. Buyers use these verification records to ensure that cell enclosures will not fail during vehicle operation. Consistent hardness ensures structural integrity.