METHOD FOR PRODUCING RAW PLATE FOR SURFACE TREATMENT PLATE FOR CAN USING CONTINUOUS ANNEALING

摘要

The method for manufacturing a blackplatet for tinplate and tin-free steel by continuous annealing, comprises the steps of: heating and soaking an as cold rolled steel sheet of low carbon aluminum-killed steel containing not more than 0.1% by weight C and 0.001 to 0.015% by weight N, to temperatures of not less than recrystallization point; applying a first cooling to thus heated and soaked steel sheet to temperatures of from 350 to 480 DEG C at average cooling speeds of from more than 100 DEG C/sec to less than 300 DEG C/sec; applying overaging to thus cooled steel sheet without giving reheating thereto; applying final cooling to thus overaged steel sheet to conduct temper rolling; wherein the temperatures for soaking at not less than recrystallization point are varied depending on aimed temper degree, thus keeping a heat cycle in stages succeeding to the first cooling nearly unchanged independent of the temper degree. With the method, it is possible to manufacture blackplates having different temper degrees separately and stably at a low cost covering all ranges of from soft materials to hard materials without degrading productivity and yield using a compact and inexpensive single CAL facility.