Case Hardening (Carburizing)
Engineering definition, metallurgical mechanisms, standard testing specifications, and manufacturing guidelines for closed-die forgings up to 50 kg.
Quick AnswerFeatured
A thermochemical surface hardening treatment that diffuses carbon into the solid surface of low-carbon steel parts at high temperature, followed by quenching.
Technical Explanation & Metallurgical Principles
Carburizing introduces carbon into the outer layer (case) of components forged in low-carbon alloy steels (AISI 8620, 20MnCr5, AISI 1018) up to 900°C–940°C in an endothermic atmosphere. Subsequent oil quenching produces a glass-hard, wear-resistant martensitic surface (58–62 HRC) while maintaining a tough, shock-absorbing low-carbon core.
Key Engineering Specifications & Parameters
| Technical Parameter / Metric | Engineering Benchmark / Value |
|---|---|
| Furnace Temp | 900°C – 940°C with controlled carbon potential |
| Case Depth | 0.5mm to 3.0mm depending on cycle time |
| Surface Hardness | 58 – 62 HRC (core: 28 – 36 HRC) |
Application at Jayesh Forge (Rajkot Plant)
Supplied on Tier-1 automotive and tractor transmission gear blanks, pinion shafts, and excavator bushes forged strictly up to 50 kg.
Related Materials, Standards & Products
Engineered Product Lines
Related Metallurgical & Testing Terms
Induction Hardening
A rapid surface hardening process where electromagnetic induction heats the outer layer of medium-carbon steel parts above transformation temperature, followed by immediate quench spray.
Quenching and Tempering (Q&T / Hardening)
A two-stage thermal strengthening process: rapid liquid cooling from austenitizing temperature to form martensite, followed by reheating to restore toughness.
Rockwell Hardness Testing (HRC / HRB)
A direct-reading indentation hardness test measuring the permanent depth of penetration produced by a diamond spheroconical indenter (Scale C) or steel ball (Scale B).
Questions Regarding Case Hardening (Carburizing)
Through-hardened gears are brittle across their entire section and can shatter under shock; case-hardened gears resist tooth wear while the ductile core absorbs heavy shock loads.
Request a Forging Quote with Case Hardening (Carburizing) Compliance
Our Rajkot metallurgy desk is ready to review your technical drawings, testing protocols, and delivery schedules for custom closed-die forgings strictly up to 50 kg.