Abstract: Addressing the heat treatment characteristics of the 30Mn steel,the approximate CCT curve and the hardenability of the 28Mn2 steel is obtained by means of the analogous comparison method.Based on the analysis,a roller-hearth continuous heat treatment furnace for one-side quenching-cooling is developed to treat oil well-service pipes (OCTG) with a size range under Ф114.3 mm×6.35 mm.The operation result shows that the hardness value of the pipes as quenched and cooled with the said furnace has been up to relevant requirement of API Spec.5CT.