Question

The Larson-Miller parameter is used to:

• A. Estimate the fatigue life of materials under variable loading
• B. Predict the creep rupture life of materials at high temperatures
• C. Determine the fracture toughness of materials
• D. Assess the impact resistance of materials

Hint:

Use the Larson-Miller parameter to predict how long a material will last under stress at high temperatures — it combines time and temperature into a single predictive model.

Answer 1

The Correct Option is B

The Larson-Miller parameter (LMP) is a tool used in materials science to predict the long-term creep rupture life of materials operating at elevated temperatures.
Creep is the slow, time-dependent deformation of materials under constant stress, especially significant at high temperatures. The LMP combines both time and temperature into a single value using the formula: \[ \text{LMP} = T (C + \log t) \] where:
- \( T \) is the absolute temperature in Kelvin,
- \( t \) is the time to rupture,
- \( C \) is a material constant (typically around 20).
This parameter allows engineers to extrapolate creep data over long durations from shorter-term tests, making it invaluable for materials selection in boilers, turbines, and other high-temperature environments.