DUAL-LAYER ISOTHERMAL SPHEROIDIZING ANNEALING HEAT TREATMENT DEVICE FOR BEARING STEAL BAR PIPE MATERIAL

摘要

A dual-layer isothermal spheroidizing annealing heat treatment device for bearing steal bar pipe material, comprising: a furnace body (1), the furnace body (1) being divided into a centrally-located heating and holding zone (13), and, sequentially and symmetrically arranged on either side of the heating and holding zone (13) from near to distant, intermediate cold zones (12, 14), isothermal zones (11, 15), and heat exchange zones (10, 16); a furnace roller assembly (2), comprising upper and lower furnace roller sets (20, 21); and a cooler (3) comprising upper and lower cooling units (30, 31). The upper cooling unit (30) comprises a circulating fan (30a), a flow guide tube (30b), and an exhaust pipe (30c), airflow expelled from the exhaust pipe exchanging heat with bearing steel bar pipe material on the lower furnace roller set (21) and then flowing to the upper furnace roller set (20) and continuously absorbing heat, and then flowing to the lower roller set (21) and performing heat exchange, forming a circulating airflow. The lower cooling unit (31) comprises a heat exchange pipe (31a), a fan (31b), and an exhaust pipe (31c). The present heat treatment device, under the condition of utilizing surplus heat, shortens the cooling time in the intermediate cold zones (12, 14), guarantees heat treatment time in the isothermal zones (11,15), and improves heat treatment quality, while also rapidly carrying away heat energy by means of a flowing airflow, thereby allowing for rapid cooling of the bearing steel bar pipe material.