Cold rolling and nitriding treatment technology of seamless steel pipe

Cold rolling of seamless steel pipes is to transform martensite into seamless steel pipes before the rolled pieces enter the precision extrusion equipment. Rough rolling is still carried out under fully martensitic conditions, and then the hot strip is brought to below temperature following an ultra-rapid cooling system between the finishing and roughing mills before entering the first finishing mill.

The nitriding treatment method of seamless steel pipe is mainly to use a nitriding furnace, put the seamless steel pipe into the material rack, and then hoist the product to the bottom of the furnace for heating. In addition, a nitriding furnace with a design scheme for lifting the load capacity of the furnace door can be produced, and the workpiece of the wall-mounted product can be heated according to the special tools for hoisting and wall-hanging. The nitriding furnace shell is generally driven by a geared motor and an electric automatic lift. After the furnace cover is closed, another clamping anchor bolt ensures the sealing of the vacuum pump of the nitriding furnace. First vacuum packaging, and then into nitrogen for heat treatment and nitriding process.

Nitriding treatment of seamless steel pipe refers to a heat treatment method in which the product is subjected to organic chemical heat treatment by a certain substance at a certain temperature. The application of nitriding furnace for vapor nitriding heat treatment of various steel mechanical parts, car curved glaze, transmission gear, motorcycle brake pads, molds, etc. has great practical value. In terms of color plates, air conditioner copper tubes, copper coins, copper core wires, copper rods, etc. can be used for bright and air-free oxidation quenching in a maintenance atmosphere. Or the air-free oxidation quenching heat treatment method used by vacuum pump N2 on thick-walled seamless tubes, short shafts, and various metal material parts.

Obviously, because the heating temperature of the cold-rolled slab in the seamless steel pipe area is lower than that of the basic cold-rolling, the heating energy consumption is greatly reduced, and the output of the heat treatment furnace is improved. Low temperature can also reduce the heating rate of hot-rolled strip, thereby reducing fatigue cracking and cracking caused by internal stress, and reducing the wear of hot-rolled strip; ultra-low temperature cold rolling can also reduce the production of secondary zinc ash and improve the quality of hot-rolled products. Process performance, and can improve the operation rate of the pickling passivation line. After the actual production verification, the hot-rolled sheet produced by the hot-rolling of the seamless steel pipe area can replace the traditional cold-rolled and quenched hot-rolled sheet, which can greatly reduce the product cost.