tsementiit, mis moodustub terapiiridel feriidist väga väikese süsinikusisaldusega teraste (alla 0,05 % C) aeglasel jahtumisel temperatuuridel alla A1 (727 oC) (vt tsementiit, ferrit; vrd primaartsementiit, sekundaartsementiit), cementite precipitated from ferrite in low-carbon (below 0.05 wt% C) steels along ferrite grain boundaries upon slow cooling from temperatures lower than A1 (below 727 oC) (see: cementite, ferrite; compare: primary cementite, secondary cementite/proeutectoid cementite)