Journal of Applied Mechanics Reviews and Reports
ISSN: 3069-0803 | DOI: 10.64030/3069-0803
Mohammad Yaghoub Abdollahzadeh Jamalabadi
This paper presents a systematic parameter study of carburization and quenching for a 2D steel spur gear (pitch diameter 100 mm, 20 teeth) using coupled multiphysics finite element simulation. The investigation examines four key process parameters— carbon potential (0.55–0.95 wt.%), mass transfer coefficient (0.5–5.0×10â»âµ cm/s), carburization duration (4–24 h), and quench oil heat transfer coefficient (1000–5000 W/m²•K)—on carbon concentration profiles, martensite start temperature distributions, phase fractions, residual stress fields, and Effective Case Depth (ECD). A complete four-step computational chain derives ECD: (1) Fickian diffusion with Robin boundary conditions solved by finite differences; (2) carbon-dependent Mâ?? mapping (Mâ?? = 560 − 470c); (3) Koistinen-Marburger martensite fraction model; and (4) Maynier hardness formulation, yielding baseline ECD = 1.636 mm at the ISO 2639/AGMA 2101 threshold of 550 HV. The framework is validated against 20 peer-reviewed studies (2022–2025). Results demonstrate that carbon potential and carburization time exert dominant influence on case depth (sensitivity indices Sáµ¢ = 1.6–1.8 and 1.2, respectively), while quench oil severity primarily governs residual stress magnitude at the tooth root (Sáµ¢ = 1.6). The 115-second transformation time differential between core and surface Mâ?? crossings quantifies the compressive stress mechanism. ECD sensitivity analysis confirms approximate √t scaling with carburization time, establishing quantitative process design charts for the 100 mm gear geometry. The study concludes with synthesis of research gaps identified in current literature, including latent heat effects, tensor-valued transformation plasticity, and 3D geometry requirements.