Pearlitic transformation temperature
The pearlitic transformation temperature is the point at which austenite transforms into ferrite and cementite. This occurs by cooling austenite below this temperature.
Physical-Chemical Mechanism
Perlitic transformation temperature is the threshold below which austenite (a high-molecular phase) decomposes into ferrite and cementite (a low-molecular phase). This process occurs when austenite cools below this temperature.
Metallurgical Relevance & Welding Risks
If the perlitic transformation temperature is not correctly maintained, uneven hardness and stress buildup can occur in the weld. This leads to increased susceptibility to cracking and fracture. Additionally, the mechanical strength of the weld can be compromised.
Workshop Practice & Actions
To achieve the correct perlitic transformation temperature, the cooling rate of the molten material must be controlled. This can be done by choosing the right welding process and parameters. For steels with high austenite content, it's important that cooling is slow enough to create a homogeneous pearlite structure. The specific temperature for perlitic transformation varies by steel type and should be listed in the material data sheet.