E-mail : inquiry@ronsteel.comPhone : +8615308477503
We are committed to providing one-stop service for steel pipe products to customers around the world.
High-temperature environments pose one of the greatest challenges to engineering materials. Components used in gas turbines, furnaces, heat exchangers, and aerospace engines are constantly exposed to extreme heat. A common question arises: Why do materials fail at high temperatures?
Understanding the mechanisms behind high-temperature failure is essential for improving safety, efficiency, and service life. This article explains the physical and chemical reasons materials lose performance under high-temperature conditions.
In materials engineering, “high temperature” generally refers to conditions where:
The material reaches 0.3–0.5 of its melting temperature (in Kelvin)
Mechanical and chemical properties begin to degrade
For many metals, this means temperatures above 400–600°C.
As temperature increases, atomic vibrations intensify, weakening the bonds between atoms. This leads to:
Reduced yield strength
Lower tensile strength
Decreased hardness
Even strong alloys may lose a significant portion of their load-bearing capacity at elevated temperatures.
Creep is a time-dependent, permanent deformation that occurs under constant stress at high temperatures. It is one of the most critical failure mechanisms in high-temperature applications.
Creep occurs in three stages:
Primary creep (decreasing rate)
Secondary creep (steady rate)
Tertiary creep (rapid deformation leading to rupture)
Without proper design, creep can cause catastrophic failure even at stresses well below the material’s room-temperature strength.
Repeated heating and cooling cycles cause thermal expansion and contraction. Over time, this cyclic stress leads to:
Crack initiation
Crack propagation
Final fracture
Thermal fatigue is especially common in components subjected to frequent startup and shutdown cycles.
At high temperatures, metals react more rapidly with oxygen, sulfur, and other elements in the environment. This results in:
Oxide scale formation
Material loss
Surface cracking or spallation
In severe cases, hot corrosion caused by molten salts can dramatically accelerate material degradation.
High temperatures can alter the internal structure of materials:
Grain growth reduces strength
Precipitates may dissolve or coarsen
Phase transformations may occur
These microstructural changes often lead to irreversible property loss.
Materials designed for high-temperature service, such as nickel-based superalloys, incorporate features like:
Solid-solution strengthening
Precipitation hardening
Stable grain structures
Protective oxide-forming elements (Cr, Al)
These characteristics help maintain strength and stability under extreme heat.
Material failure at high temperatures is not only a material issue—it is also influenced by:
Component design
Stress concentration
Operating duration
Temperature fluctuations
Maintenance practices
Poor design or misuse can cause even advanced materials to fail prematurely.
Effective strategies include:
Selecting heat-resistant materials
Reducing applied stress
Improving cooling systems
Applying protective coatings
Monitoring temperature and service time
Preventive maintenance and proper engineering design are critical.
Why do materials fail at high temperatures? Because heat fundamentally alters mechanical strength, accelerates chemical reactions, and changes internal structures. Understanding these failure mechanisms allows engineers to select better materials, design safer systems, and extend component life in extreme thermal environments.
