Answer: If the temperature of a piece of steel decreases its density will increase.
Step-by-step explanation:
When the temperature of the the substance increases the volume of the substance also increases.This means that the temperature is directly proportional to the volume.
The density of the substance is defined as the mass per unit volume.

Since ,the volume is inversely proportional to density and temperature is directly proportional to the volume. So, on decreasing the temperature, the volume of the steel will decrease and by this decrease in volume the density of the steel will increase.