1. High strength and wear resistance
18CrNiMo7-6 is widely used in the manufacturing of gears due to its high strength and wear resistance. Its main alloying elements such as chromium, molybdenum, and nickel form a hardened layer on the surface of the gear through appropriate heat treatment processes (such as carburizing treatment), significantly improving the surface hardness and wear resistance of the gear. According to the ISO 6336 standard, high hardness gear surfaces can effectively reduce friction and wear, extending the service life of gears.
Specifically, carburizing treatment can form a hardened layer on the surface of the gear, with a hardness of HRC 58-62, while the core maintains a relatively low hardness to ensure its toughness and load-bearing capacity. This hardened layer can effectively resist wear under high loads and high speeds, reduce gear wear and replacement frequency, and improve operational efficiency.

2. Good hardenability
18CrNiMo7-6 has excellent hardenability, which means it can maintain uniform hardness during the quenching process. This characteristic enables gears to maintain stable performance under high loads. According to ASTM A255 standard, the hardenability test can evaluate the hardness distribution of materials at different depths. For 18CrNiMo7-6, its excellent hardenability ensures that ideal hardness can be obtained throughout the thickness range of the gear, preventing gear failure caused by uneven local hardness.
3. High resilience
The high toughness enables 18CrNiMo7-6 to withstand large impact loads without brittle fracture. According to ISO 148 standard, toughness testing evaluates the performance of materials in impact testing. 18CrNiMo7-6 has high elongation and cross-sectional shrinkage, which means it can undergo moderate deformation without fracture when subjected to impact forces. This is particularly important for rail train gears to withstand impact forces from the track and wheels in practical use.
4. Excellent processing performance
Although 18CrNiMo7-6 has higher hardness after quenching, its machinability is still good. Especially in gear grinding, the machinability of materials directly affects the manufacturing accuracy and consistency of gears. Good processing performance can reduce waste and processing difficulty in the production process, ensure high precision and stability of gears, and thus improve production efficiency.
5. Standardization requirements
18CrNiMo7-6 complies with the EN 10084 standard, providing manufacturers with clear quality and performance benchmarks. Standardization requirements ensure the stability of the production process and help maintain product consistency and reliability. This standardization has made 18CrNiMo7-6 highly recognized and applicable globally, providing a solid guarantee for the safe and stable operation of rail trains.