Phosphorus cold brittleness
Phosphorus cold shortness is a tendency of metals to brittle fracture at room temperature, caused by phosphorus at the grain boundaries. This leads to a strong reduction in impact toughness.
Physikochemical mechanism of action
Phosphorus cold brittleness occurs when phosphorus is precipitated at the grain boundaries of metals. This leads to a brittle structure in the material that breaks easily under mechanical stress.
Metallurgical relevance & risks in welding
This brittle structure can arise from incorrect welding parameters or insufficient cleaning. It leads to a severe reduction in impact toughness and increases susceptibility to cold cracking, especially under mechanical loads.
Workshop practice & instructions
To avoid phosphorus cold brittleness, it is important:
• Clean the weld thoroughly and cover it with phosphorus-free materials.
• For high-phosphorus steels, use a high melting temperature and controlled cooling.
• Check impact toughness after welding and, if necessary, carry out additional treatments such as austenitizing.