EN 10277-6 (EU) and GB/T 3077 20CrMnTi (China) cover case-hardening steels with key similarities and differences:
Grade equivalence: EN 10277-6 18CrNiMo7-6 ≈ 20CrMnTi, but 20CrMnTi uses titanium (0.04–0.10%) instead of molybdenum for grain refinement during carburizing.
Carburizing performance: 20CrMnTi achieves a deeper, harder case (58–62 HRC) with a tougher core (30–35 HRC) than 18CrNiMo7-6, making it better for high-wear gears.
Mechanical properties: Both have 800–1000 MPa tensile strength after carburizing, but 20CrMnTi offers higher surface hardness due to titanium carbides.
Applications: 18CrNiMo7-6 dominates EU automotive transmissions, while 20CrMnTi is preferred in Chinese gear manufacturing for its lower cost and superior case quality.