Abstract: A seal roll apparatus and method hermetically seals boundaries between a plurality of heat-treating sections for continuously heating and cooling a strip material in a continuous heat-treatment furnace. The seal roll apparatus includes a seal roll room including at least a pair of water-cooled seal rolls opposed to each other with a gap therebetween for passing the strip material, and partitions having an opening for passing the strip material, a partition being provided at the inlet side and at the outlet side of the seal rolls.

Abstract: A continuous heat treatment furnace having one of a plurality of furnace zones except for first and last zones as a rapid cooling zone 11 for rapidly cooling a material by blowing an atmospheric gas, which comprises a roll-sealed chamber 3 partitioned at the inlet by first and second roll sealing devices 4A and 4B from the upstream and a third roll sealing device 4C at the outlet as sealing means for atmospheric gas, and in which the inlet of the first roll sealing device and the outlet of the third roll sealing device are connected, and/or the roll-sealed chamber and an uppermost stream portion 6 in the rapid cooling zone are connected, and in which the hydrogen concentration in the furnace is controlled to 10% or higher in the rapid cooling zone and is controlled to 10% or lower in the furnace zone at the inlet of the rapid cooling zone.

Abstract: An apparatus in which a metal strip is passed in contact partly around the outer circumferences of a number of spaced cooling rolls through which coolant passes. The apparatus includes temperature detectors for detecting the temperature of the strip before contact with each of the cooling rolls, and coolant temperature regulators controlled in accordance with the detected temperature of the strip to adjust the temperature of the coolant passing through each cooling roll to a range which limits the temperature drop of the strip such that unacceptable irregularities or distortions in the configuration of the strip cannot occur. The coolant used for each cooling roll is selected with a boiling point appropriate to the respective detected temperature for each roll. In the preferred arrangement, further temperature detectors are provided for each cooling roll to detect the temperature of the coolant, and output signals from both detectors are inputted to a control for regulating a flow rate valve.