Microstructural stability
Microstructural stability is a metal's resistance to phase changes and grain growth under mechanical or thermal stress. It affects the material's strength, hardness, and toughness.
Physical-Chemical Mechanism of Action
The microstructure of a metal consists of different phases such as crystal cells and grains. Under thermal or mechanical stress, these phases can change or grow, compromising the structure.
Metallurgical Relevance & Welding Risks
Low microstructural stability leads to uneven grain sizes and phase distributions, reducing the material's strength and toughness. This can cause cracks, wear, and reduced component lifespan.
Workshop Practice & Procedures
To improve microstructural stability during welding:
• Ensure optimal arc time (approx. 2 to 3 seconds for steel).
• Set the cooling throttle correctly to ensure controlled cooling.
• For high stresses or temperatures, use additional coolants like water spray.