JPH0751724A - Method for annealing, pickling hot rolled stainless steel strip and equipment therefore - Google Patents

Abstract

PURPOSE:To remove surface faults at real time by winding into a coil after removing faults of the surface of a steel strip by manually or automatically grinding fault generated places with grinding brush rolls. CONSTITUTION:A hot rolled stainless steel strip S is annealed in a continuous annealing furnace 4 (martensite base and ferrite base are not heated), passes though a mechanical scale breaker 5 (MSB), next through a shot blast device 6 and enters in a pickling tank 7. The heat treated strip S after pickling is inspected with a sheet surface inspecting device installed in a surface inspecting room 1, only parts with surface faults are ground with the grinding brush roll 2, and wound in a coil with a tension reel 3. The grinding brush roll 2 consists of heavy grinding brush rolls. Therefore, the surface faults can be removed at real time, further if it is connected to an automatic grinding device, the parts of surface faults are automatically removed with grinding, the achievement ratio of its delivery time is improved and the cost is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an annealing pickling method and equipment for hot rolled stainless steel strip.

[0002]

2. Description of the Related Art Generally, in the case of austenitic stainless steel, hot-rolled stainless steel strip is continuously annealed in a continuous annealing pickling line and then pickled.
In the case of ferritic stainless steel, first, batch annealing is performed in a batch furnace, and then only pickling is performed in a continuous annealing pickling line to obtain a hot rolled steel strip product. At this time, it is usual to inspect the surface after pickling.

As a result of the inspection, the steel strip which has many surface defects and is determined to be unacceptable as a product is carried to the surface grinding line in the next step, and after the surface defects are ground and removed, it is made into a product.

[0004]

Thus, after passing through the continuous annealing pickling line, inspecting and winding up, the rejected coil is passed through the surface grinding line again and the steel plate surface flaws are ground and removed. However, in the method described above, the number of process steps increases and the number of process days increases, resulting in a delay in delivery. In addition, the surface grinding line requires a very large tension during grinding,
Since the equipment is large, and the shavings (sludge) generated during grinding are mixed in the grinding oil, a large sludge treatment equipment was required.

The present invention solves the above problems and provides an annealing pickling method and equipment for removing the surface defects of a hot rolled stainless steel strip by grinding the surface defects without increasing the number of passing steps. That is the purpose.

[0006]

According to the present invention, a hot-rolled stainless steel strip is annealed, continuously pickled, and wound on a coil after plate surface inspection. A method for annealing and pickling a hot-rolled stainless steel strip, which comprises winding a coil after removing a flaw on the surface of the steel strip by grinding with a grinding brush, and the present invention is a continuous annealing furnace followed by continuous acid pickling. In an annealing pickling equipment for hot rolled stainless steel strips having a washing device, a plate surface inspection device and a coil winding device, grinding for removing surface flaws of the steel strip between the plate surface inspection device and the coil winding device An annealing and pickling facility for hot-rolled stainless steel strips, characterized in that brush rolls are provided. In the present invention, the grinding brush roll is preferably composed of a heavy grinding brush roll.
Here, the heavy-grinding brush roll has a diameter of 3 mm containing abrasive grains as disclosed in JP-A-4-315582.
The rod-shaped body described above is radially mounted on the roll shaft, and has a polishing performance almost equal to the polishing performance of a grinding wheel and a polishing disk.

More specifically, the diameter containing the abrasive grains is 3 mm.
In a heavy-grinding brush roll mounted with the above rod-shaped body on the roll shaft radially with respect to the shaft circumference via a spring material and in a state gathered in the axial direction, the rod-shaped body and a spring combining the same The grinding element body made of material is arranged in a spiral shape, and the angle between the surface in the roll axis length direction and the surface of the threading arrangement of the grinding element body is 3 degrees or more, and the grinding element body moves in the adjacent direction. It is a brush roll in which each of the grinding element bodies is provided with an enormous part for regulating

Since the grinding ability of one heavy grinding brush roll is determined, a plurality of heavy grinding brush rolls can be installed in series depending on the type of steel strip and the type of flaw to be removed by grinding.

[0009]

According to the present invention, since the grinding brush roll for removing surface flaws is installed downstream of the surface inspection apparatus of the continuous annealing pickling line for hot rolled stainless steel strips, surface flaws found at the time of inspection can be manually or By automatically operating the grinding brush roll, it becomes possible to grind and remove only the flaw portion in real time.

As a result, the number of coils required to pass the surface grinding line after the continuous annealing pickling line can be reduced, and the number of process days and the cost of passing the surface grinding line can be reduced.

[0011]

EXAMPLE FIG. 1 is a schematic view of a continuous annealing pickling line for hot-rolled stainless steel strips showing an example of the present invention, and FIG. 2 is a partial detailed view thereof. Here, the hot rolled stainless steel strip S is annealed in the continuous annealing furnace 4 (no heat treatment for martensite type and ferrite type), passes through the mechanical scale breaker (MSB) 5, and then passes through the shot blasting device 6 and the pickling tank 7 to go into. The hot-rolled steel strip S after pickling is inspected by a plate surface inspection device (not shown) provided in the surface inspection chamber 1, only a portion having a surface flaw is ground by the heavy grinding brush roll 2, and the tension reel 3 is used. It is wound into a coil.

FIG. 3 shows the transition of the occurrence rate of the coil which requires further flaw removal before and after the heavy grinding brush roll is installed in the continuous annealing pickling line for hot rolled stainless steel strip in FIG. Since a heavy grinding brush roll was installed after the surface inspection and the surface flaws found could be ground and removed in real time, the incidence of coils for the surface grinding line was halved as shown in the figure. Since the surface flaws at this time are targeted for the flaws caused by hot rolling, which is relatively mild, called line hegging, it is only halved in this way.
Further, by increasing the number of heavy grinding brush rolls or decreasing the plate passing speed, it is possible to deal with severe defects and to further increase the reduction rate.

FIG. 4 is a graph showing the relationship between the number of heavy grinding brush rolls installed and the grinding ability. It can be said that three stands of heavy grinding brush rolls are required for the grinding of the line hair.

[0014]

EFFECTS OF THE INVENTION According to the present invention, in the continuous annealing pickling line for hot rolled stainless steel strips, the surface flaw removing grinding brush roll is installed on the outlet side of the surface inspection apparatus, so that the surface flaws can be removed in real time. became. Further, if the automatic flaw inspection device is connected, the surface flaw portion can be automatically ground and removed.

As a result, the delivery rate of the hot rolled stainless steel strip can be improved and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an equipment arrangement of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a graph showing a transition of a generation rate of a coil requiring flaw removal before and after installation of a heavy grinding brush roll.

FIG. 4 is a graph showing the relationship between the number of heavy grinding brush rolls installed and the grinding depth.

[Explanation of symbols]

 1 Surface inspection room 2 Double grinding brush roll 3 Tension reel 4 Annealing furnace 5 Mechanical scale breaker (MSB) 6 Shot blast 7 Pickling tank

Front page continuation (72) Inventor Junichi Yamamoto 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Prefecture Kawasaki Steel Co., Ltd. Chiba Works (72) Inventor Fumio Yokozawa 1 Kawasaki-cho, Chuo-ku, Chiba Chiba Inside the Chiba Works (72) Inventor Seto Hotani 1452 Foki, Nogami-cho, Seagrass-gun, Wakayama Hotani Co., Ltd.

Claims (3)

[Claims] 1. A hot-rolled stainless steel strip is annealed, continuously pickled, and wound on a coil after plate surface inspection, where a flaw is generated by manually or automatically grinding with a grinding brush roll. A method for annealing and pickling a hot rolled stainless steel strip, which comprises winding a coil after removing a flaw on the surface of the steel strip. 2. An annealing pickling equipment for hot rolled stainless steel strip, which comprises a continuous pickling device, a plate surface inspection device and a coil winding device following the continuous annealing furnace, wherein the plate surface inspection device and the coil winding device are provided. An annealing pickling facility for hot-rolled stainless steel strips, characterized in that a grinding brush roll for removing surface flaws on the steel strips is provided between and. 3. The annealing pickling apparatus for hot-rolled stainless steel strip according to claim 2, wherein the grinding brush roll is a heavy grinding brush roll.