We conducted a series of tests on 4145H and 35CrMo round steel bars of the same specifications, including chemical composition, end-quench hardenability, non-metallic inclusions, grain size, macrostructure, and microstructure.
1. Chemical Composition
Comparing the chemical compositions of 35CrMo and 4145H (Table 1), 4145H exhibits higher carbon content and elevated levels of alloying elements such as Mn, Ni, and Mo. Theoretically, this suggests that 4145H offers superior hardenability and quenching performance compared to 35CrMo.
2. End-Quench Hardenability
To verify this, we performed end-quench hardenability tests on both materials and plotted their hardenability curves. The results show that 4145H’s curve remains nearly horizontal, with hardness at 48 mm from the quenched end showing no significant drop from the surface. In contrast, 35CrMo’s curve declines noticeably with a clear slope. This demonstrates that 4145H possesses excellent hardenability, significantly outperforming 35CrMo.
3. Non-Metallic Inclusions and Grain Size
In tests of non-metallic inclusions and grain size for 4145H and 35CrMo round bars of the same specifications, both materials displayed comparable levels, with no substantial differences.
4. Macrostructure
When examining the macrostructure of 4145H and 35CrMo round bars, the two materials showed similar quality levels, though 4145H slightly outperformed 35CrMo.
In summary, 4145H demonstrates advantages over 35CrMo, particularly in chemical composition and hardenability, while maintaining comparable performance in non-metallic inclusions, grain size, and macrostructure. These properties highlight 4145H’s potential for applications requiring enhanced mechanical performance.
Post time: Apr-11-2025
