Cast iron stands up well to fire and intense heat, but it may ______ or ______ when rapidly cooled with water.

• A. Warp or bend
• B. Crack or shatter
• C. Melt or dissolve
• D. Crack or warp

Answer: (B)

When metal is heated and then cooled rapidly, thermal shock can cause stresses that break the material. Cast iron is brittle and has limited ductility, so it doesn’t bend or warp plastically under stress. Instead, the rapid cooling from water creates intense surface contraction while the interior remains hotter and expands differently, generating tensile stresses that exceed the iron’s fracture strength. That leads to cracking or shattering, not bending. The other options involve plastic deformation or melting, which don’t fit the way cast iron behaves under quick quenching.