Question

For a certain high-temperature alloy, failure was reported after 353 hrs at 725°C when subjected to a stress level of 270 MPa. If the same stress were applied at 500°C, how long would the component be expected to last?

Answer 1

To determine how long the component would last at 500°C with a stress level of 270 MPa, we use the Larson-Miller parameter. Given that failure occurred after 353 hours at 725°C, we can calculate a value for the Larson-Miller parameter and then use it to find the expected lifetime at 500°C. The component would be expected to last approximately 2048.37 hours at 500°C with a stress level of 270 MPa.

Step-by-step explanation:

To determine how long the component would last at 500°C with a stress level of 270 MPa, we need to use the Larson-Miller parameter. The Larson-Miller parameter is given by the equation LM = (T+273) * log(t), where T is the temperature in Kelvin and t is the time in hours. We can rearrange this equation to solve for t, which gives us t = 10^((LM / (T+273))).

Given that failure occurred after 353 hours at 725°C, we can plug these values into the Larson-Miller parameter equation to find the value of LM at the given condition.

LM = (725+273) * log(353) ≈ 11209.08

Next, we can use this value of LM to solve for t at 500°C:

t = 10^((11209.08 / (500+273))) ≈ 2048.37 hours.

Therefore, the component would be expected to last approximately 2048.37 hours at 500°C with a stress level of 270 MPa.