Effect of Trap Spatial Distribution on Equilibrium Hydrogen Partitioning in Bearing Steel During Loaded Standstill

Abstract

Hydrogen absorbed during bearing operation can redistribute under contact stress retained during loaded standstill. This study examines how trap spatial distribution changes equilibrium lattice hydrogen at equal total trap capacity. Using the published 100Cr6–81104-TV configuration and a selected total inventory of 1.5 wppm, fixed profiles were compared under maintained chemical potential and retained inventory. Established equilibrium relations were used to derive capacity- and occupancy-dependent concentration bounds, including finite limits on local trap density. Under retained inventory, allocating traps to locations with a higher occupancy at a common activity increased storage and lowered lattice hydrogen. At the maintained chemical potential, the trap position changed the trapped hydrogen but left the lattice hydrogen unchanged. At 90 °C, the low-capacity benchmark gave a negligible positional effect. A theoretical capacity-matched state gave a 3.07% difference between two layers, while the density-limited mean range was 19.28%. Inventory, binding-energy, and residual-stress sensitivities identify the conditions governing these comparisons. Conditional linear relaxation bounds show that excess-capacity states can contain very slow modes. The concentration bounds screen spatial trapping effects within the prescribed equilibrium model; their application to an operating hold requires evidence of sufficient relaxation and the assumed hydrogen boundary.

The authors' abstract, as published at the source. Applied Sciences, 2026 · DOI ↗