Background
A leading tractor OEM faced high rejection rates due to hydraulic failures in the bush and spool assembly of its hydraulic lift system. Made from SAE 8620 and finished through honing, the parts often exhibited dimensional variation and surface wear, contributing to inconsistent hydraulic pressure and lift malfunctions.
Cryogenic Solution
The bush and spool components were treated using a deep-cryogenic cycle tailored for carburizing-grade steels. The treatment refined microstructure uniformity, enhanced dimensional stability, and improved wear resistance—without altering design, process, or base material.
Quantified Results
| Metric | Pre-Cryogenic | Post-Cryogenic | Improvement |
|---|---|---|---|
| Hydraulic failure rate | 27 % | 0 % | Eliminated |
| Pressure drop incidents | Frequent | None observed | – |
Additional Benefits
- High dimensional stability and reduced variation after honing.
- Smoother surface finish post-finishing, supporting better sealing and fit.
- Drastically reduced wear, extending part life in field conditions.
- Hydraulic pressure maintained, improving lift reliability and long-term performance.
Takeaway
Deep-cryogenic treatment of bush and spool components completely eliminated hydraulic failures, solving a persistent reliability issue in the tractor's lift system. Enhanced dimensional stability and reduced wear helped maintain hydraulic integrity, showcasing cryogenics as a powerful upgrade for critical motion-control parts in agricultural machinery.