Let us see a case study about the thermal expansion of mold components described in the last course.

Question:

The overall length of a core pin prepared in a 20°C machine formation room was 30.52 mm. When this core pin is heated to 150°C, how long is the amount of thermal expansion? The material of the core pin is pre-hardened steel of the SCM440 series.

Sample Answer:

The equation for calculating the thermal expansion of metals is the following. Let us substitute the values in this equation.

Where λ is the elongation (mm) of the core pin due to thermal expansion and α is the linear thermal expansion coefficient of the metal (mm/mm).
In the case of a pre-hardened steel of the SCM440 series, α = 11.5 x 10^-6 mm/mm, ｌ_０　is the initial length of the core pin (mm), ｌ_０= 30.52 mm, t is the initial temperature (°C), t = 20°C, and　ｔ_０　is the temperature after heating (°C), ｔ_０ = 150°C.
Therefore, λ = 11.5 X 10^-6 X 30.52 X (150-20) = 0.0456 (mm).