Dislocation production in alpha Fe-C alloys by rapid heating

It is demonstrated that metastable carbide particles in α-Fe act as sources of dislocations when heated rapidly to a temperature where the particles are unstable. The type and arrangement of such dislocations are dependent on the rate of heating. At moderate heating rates, the particles produce well-defined groups of equally spaced interstitial dislocation loops lying on {100} planes, with Burgers vectors ofa<100>. Cementite (Fe₃C) particles of comparable size dissolve without producing dislocations. The original metastable particle sites retain carbon in the form of small globular particles which may be graphite. At faster heating rates, the dislocation arrangement becomes more disorderly with both b =a<100> and b =a/2<111> dislocations emanating from the same particle.