Thermal shock behavior of refractories: The ability of a refractory brick to withstand sudden temperature changes without cracking is known as what?

Introduction / Context:
Refractory linings experience rapid heating and cooling during start-ups, shutdowns, and process fluctuations. A key property determining service life under such conditions is the material’s resistance to thermal shock, often discussed in terms of resistance to spalling (fragmentation or flaking due to thermal stresses).

Given Data / Assumptions:

• Thermal shock is induced by steep temperature gradients and resulting thermal stresses.
• Terminology distinguishes between high-temperature strength (refractoriness, RUL) and thermal shock performance (spalling resistance).
• We seek the correct property name for sudden temperature change endurance.

Concept / Approach:
Spalling resistance is the recognized term describing a refractory’s ability to resist crack initiation and propagation under rapid temperature cycling. It depends on thermal expansion, thermal conductivity, elastic modulus, and microstructural features such as porosity and crack-bridging phases. It is distinct from refractoriness (ability to withstand high temperature without softening) and RUL (deformation under load at temperature).

Step-by-Step Solution:

Verification / Alternative check:
Thermal shock testing methods (e.g., water quench, flame impingement cycling) are used to quantify spalling resistance, confirming the property’s distinct identity.

Why Other Options Are Wrong:

• Refractoriness: Measures softening/melting behavior, not thermal shock endurance.
• RUL: Measures creep/deformation under load, not crack resistance during quench.
• None of these: Incorrect because spalling resistance is the standard term.

Common Pitfalls:
Assuming high refractoriness implies good thermal shock resistance; many ultra-refractory oxides can be brittle and spall readily under rapid cycling.

Final Answer:
spalling resistance