Overview
ISO 22507:2022 specifies the material compositions and required properties of fluid film bearing materials for vehicular turbochargers. It defines the performance expectations for plain bearings used in turbocharger journal and thrust positions, covering seizure resistance, wear resistance and chemical corrosion resistance under the distinctive high-speed, high-temperature and contaminated-oil conditions typical of automotive turbochargers.
Key Topics and Requirements
- Material scope: Copper alloys (solid or multi-layered with steel backing) are preferred for elevated-temperature tribological performance; surface-treated steels and lead‑free aluminium‑tin alternatives are also acknowledged.
- Performance properties:
- Seizure resistance - required for extreme sliding speeds (cases >100 m/s).
- Wear resistance - needed to tolerate shaft contact, soot in oil and lower-viscosity lubricants.
- Chemical corrosion resistance - bearings must resist oil at inlet temperatures >100 °C and transient exposure >200 °C after engine stop.
- Practical composition guidance: Clause 5 and Table 1 provide example alloy compositions and typical characteristics (e.g., CuPb15Sn8, CuZn37Mn3Al2PbSi). Manufacturers may tailor compositions for specific operating conditions.
- Testing and verification: Manufacturers may use in‑house procedures or refer to standard tests (see ISO 7148‑1 for tribological testing and ISO 10129 for corrosion resistance).
- Regulatory caution: The standard warns about lead (Pb) toxicity and notes trends toward lead‑free alloys; purchaser-specified limits for elements must be agreed between supplier and purchaser.
Applications and Who Uses It
ISO 22507 is intended for:
- Turbocharger OEMs and component designers defining bearing material requirements.
- Bearing manufacturers and material suppliers developing alloys for high-speed turbo applications.
- Automotive engineering teams (powertrain, NVH, durability) selecting bearing systems for engine downsizing and emissions-driven designs.
- Test laboratories and quality/compliance units validating tribological and corrosion performance.
Practical use cases include specification of journal and thrust bearing materials, supplier contracts, material selection for high-speed turbochargers, and design decisions for floating or semi‑floating bush bearings.
Related Standards
- ISO 4378‑1 and ISO 4378‑2 - terms, definitions and tribological concepts for plain bearings.
- ISO 7148‑1 - testing tribological behaviour of bearing metals.
- ISO 10129 - lubricant-corrosion testing for bearing metals.
ISO 22507 is a concise, application-focused standard that helps ensure reliable, durable fluid film bearings in vehicular turbochargers by aligning material composition, mechanical performance and high‑temperature corrosion resistance. Keywords: ISO 22507, fluid film bearing materials, vehicular turbocharger, plain bearings, seizure resistance, wear resistance, corrosion resistance, copper alloys, journal bearing, thrust bearing.