Power Steering Systems: Low-Permeation HNBR Hoses for Hydraulic Fluid.

Power Steering Systems: Low-Permeation HNBR Hoses for Hydraulic Fluid

Problem Statement

Hydraulic power steering systems require hoses with low fluid permeation to prevent leaks and maintain system efficiency. Standard NBR hoses degrade under high-temperature hydraulic fluids, leading to swelling, cracking, and permeation losses exceeding 0.5 g/m²/day.

Material Science Analysis

HNBR (Hydrogenated Nitrile Butadiene Rubber) outperforms NBR due to its saturated backbone structure. The hydrogenation process eliminates double bonds, enhancing thermal stability and chemical resistance. HNBR resists degradation from hydraulic fluids up to 150°C, with permeation rates below 0.1 g/m²/day. Its fluorine-free formulation ensures compatibility with ATF fluids.

Technical Specs

• Shore A Hardness: 70 ± 5
• Tensile Strength: 20 MPa
• Elongation at Break: 300%
• Temperature Range: -40°C to 150°C
• Compression Set: 15% (22 hours at 150°C)

Material Comparison

Material	Permeation Rate (g/m²/day)	Temperature Range (°C)	Compression Set (%)	Chemical Resistance
HNBR	0.1	-40 to 150	15	Excellent
NBR	0.5	-20 to 100	25	Good
FKM	0.05	-20 to 200	10	Excellent

Standard Compliance

RubberQ adheres to IATF 16949 standards for batch-to-batch consistency. HNBR formulations comply with ASTM D2000 for material callouts and ISO 3601 for sealing performance. Surface preparation and bonding processes meet ASTM D429 adhesion requirements.

For custom material compound development or IATF 16949 documentation, consult RubberQ’s engineering department.