Low expandable alloys, such as Grade 4J32 and Grade 4J36, are precision materials with exceptionally low thermal expansion rates. These alloys are widely used in applications that require high dimensional stability over a range of ambient temperature changes. Their unique properties make them ideal for precision instrument components, thermostat rods, and length standards.
Key Features and Applications
Low Thermal Expansion:
Both grades are engineered to maintain dimensional stability, even with significant changes in ambient temperatures.
High Precision:
These alloys are suitable for manufacturing instrument parts requiring exact measurements and thermostatic components, ensuring consistent performance in sensitive environments.
Diverse Applications:
They are essential in length standards and precision devices that demand stability over time and temperature.
Chemical Composition (% by Weight)
Grade | C | Si | P | S | Cu | Se | Mn | Ni | Co | Fe |
4J32 | ≤0.05 | ≤0.20 | ≤0.02 | ≤0.02 | 0.40–0.80 | --- | 0.20–0.60 | 31.5–33.0 | 3.20–4.20 | Balance (Bal) |
4J36 | ≤0.05 | ≤0.30 | ≤0.02 | ≤0.02 | --- | --- | 0.20–0.60 | 35.0–37.0 | --- | Balance (Bal) |
Standard: YB/T 5241-2005
Grade-Specific Characteristics
Grade 4J32:
Contains 3.20%–4.20% cobalt, enhancing its thermal and mechanical stability.
Ideal for applications that require moderate thermal expansion control with added mechanical strength.
Grade 4J36 (Invar 36):
Known for its exceptionally low coefficient of thermal expansion, especially near room temperature.
Often used in scientific instruments, cryogenic applications, and precision engineering.
Why Choose Low Expandable Alloys?
Low expandable alloys like 4J32 and 4J36 are critical for industries where precision, durability, and stability are paramount. Their superior performance in environments with fluctuating temperatures ensures reliability and accuracy, making them indispensable in modern engineering and manufacturing.