Hadfield steel strain hardening
Manganese hard steel deformation strengthening is a mechanism in austenitic manganese castings where mechanical loads cause a martensitic transformation at the surface, creating a wear-resistant edge layer.
Physical-Chemical Mechanism of Action
During work hardening of manganese steel, austenitic manganese cast steels are transformed into a martensitic microstructure near the surface by mechanical impact or pressure loading. This happens through massive local dislocation pile-up, which strengthens the material at the surface.
Metallurgical Relevance & Welding Risks
This hardening increases the surface hardness and wear resistance, which is especially useful under high loads. However, excessive hardening can make the material prone to cracking, especially if it isn't cooled properly. Inadequate cooling can lead to a fine grain structure and reduced core strength.
Shop Practice & Action Instructions
To effectively use work hardening of manganese steel, the following measures should be observed:
• Use high load during welding to promote dislocation pile-up.
• Make sure the material is cooled properly to ensure uniform martensite formation. A cooling time of at least 10 seconds is recommended.
• Avoid excessive loads or uneven cooling, as this can lead to cracking.