If you fill a super strong metal box with water, weld it shut, and then place it in a freezer with no room for the water to expand, the water will still freeze. When water freezes, it undergoes a phase change from a liquid to a solid, resulting in an expansion in volume. This expansion can exert pressure on the container, potentially causing it to deform, crack, or even rupture.
Even if the metal box is exceptionally strong, the pressure generated by the expanding ice can exceed its structural integrity. Metals are generally not completely rigid, and they have a limit to the amount of stress they can withstand. Therefore, subjecting the box to this kind of pressure could result in damage to the container.
It's worth noting that water expands by about 9% when it freezes. To prevent damage, containers designed to hold water in freezing conditions typically incorporate features such as expansion joints, flexible materials, or extra space to accommodate the expansion.