What material is commonly used for boiler construction due to its heat resistance?

Steel or cast iron is widely used for boiler construction primarily because of its exceptional heat resistance and structural integrity. Boilers operate under high pressure and temperature conditions, requiring materials that can withstand these extreme environments without deforming or failing.

Steel, particularly when alloyed with other elements, provides a high tensile strength that allows it to handle the stresses imposed during operation. Cast iron, while somewhat more brittle than steel, offers excellent resistance to corrosion and has good thermal retention properties, making it suitable for certain boiler designs.

In comparison, aluminum, while lightweight, does not possess the necessary heat resistance and strength to be used safely in high-pressure boiler applications. Plastic materials, conversely, cannot handle the high temperatures and pressures seen in boiler systems. Copper, although good for heat transfer, does not have the same strength characteristics necessary for the structural integrity required in boiler construction under those conditions.