JPH0241701A - Manufacture of channel shape - Google Patents

Abstract

PURPOSE:To obtain channel shapes of good quality by forming a rolled stock whose shape is nearly W-shape with the curbed web and its both ends are formed in a straight line shape by a length in a limited angle centering on an extended crossing point of both flange outside faces by hot caliber rolling and then the web is flattened by roll forming. CONSTITUTION:A finally rolled shape by hot caliber rolling before a roll forming stage is such that a nearly W-shape whose web 1 is protruded and curbed in the direction of flanges 2 and both ends of the web 1 connecting to the flanges 2 are formed in a straight line shape by a length of a central angle alpha of 10-20 deg. centering on an extended line crossing point of both outside faces of the flanges 2, then the web 1 is flattened by roll forming work to manufacture a channel shape.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a groove-shaped material having a sharp and precise shape, particularly at the intersection angle (hereinafter referred to as "pin angle") between the outer surface of the web portion and the outer surface of the flange portion. This relates to a method for stably manufacturing in a process-saving manner regardless of the type of material.

<Prior art and its problems> In recent years, various structures using metal structural materials have been used in various fields and for various purposes. Demand for channel materials made from materials (including alloys) is also showing a significant growth trend.

However, with this channel material, the pin angle mentioned above is sharp and precise (9
06) For the production of materials with relatively good deformability, such as common steel, groove rolling has traditionally been adopted, as shown in Figure 7. A similar bus schedule was set up.

However, it is difficult to manufacture final shaped products by groove rolling alone with stainless steels, etc., which do not have very good deformability and are prone to seizure, so it is difficult to manufacture groove shaped products using these materials. However, the method of producing a product with a U-shaped cross section by butt welding one side of each of two angle-shaped members (angle members) was forced, which was an inefficient work.

For this reason, it has recently been reported that channel steel can be manufactured with high efficiency even when using difficult-to-process stainless steel as a material.
``Material steel is hot-hole rolled, and the wall thickness of the flange part and web part is the same as the product dimensions, and the cross-sectional shape is W-shaped with the web part protruding in the flange extension direction (i in Figure 7). Channel steel is manufactured in two steps: forming an intermediate product with the shape shown in ), and then processing the curved web part of the intermediate product into a flat shape by cold or warm roll forming. ``method'' was proposed (Japanese Patent Laid-Open No. 60-22
No. 7901, JP-A-62-279002). and,
These methods use mere "roll forming" instead of rolling to form the W-shaped cross section, which is unavoidable in groove rolling due to the "occurrence of seizure defects on the flange due to the difference in circumferential speed of the rolls." Therefore, a channel steel with good surface quality could be obtained efficiently and at an advantageous manufacturing cost.

However, although the method proposed above does not pose any particular problem when applied to materials with relatively high deformability such as ordinary steel, it does not have any problems with the deformability and deformation resistance of materials such as stainless steel and titanium. In the case of materials with difficult points, it has become clear that there are problems in ensuring the accuracy of the final product shape, such as the flatness of the web portion during the roll forming stage. Incidentally, the above-mentioned problem could not be solved even if the roll forming was carried out "warm" at 200 to 600 DEG C. as proposed in JP-A-62-279002.

Therefore, the main purpose of the present invention is to form grooves with good surface texture and shape accuracy, especially at pin corners and web parts, even from materials that have difficulty in forming, such as stainless steel and titanium. The object of the present invention is to provide a means for efficiently and inexpensively manufacturing materials.

Means for Solving the Problem> The present inventors conducted experiments and research from various viewpoints in order to achieve the above object, and found that ``In particular, it is possible to use materials that have difficulty in forming, such as stainless steel and titanium. The advantage of using two processes, hot hole rolling and roll forming, cannot be overlooked in the highly efficient production of channel shaped materials with good surface properties. The final cross-sectional shape is not "W-shaped with the web portion protruding in the flange extension direction and simply curved [see Fig. 8 (a)]" as in the previous proposal, but instead If the center of the web is curved and protrudes, but the subsequent ends are straight over a predetermined length and connected to the flange, forming a W-shape, the subsequent roll forming will be one-bath forming. It was found that "even if the web is flat, it is possible to ensure the flatness of the web, and it is also possible to secure the specified pin angle stably and reliably."In this case, when roll forming is performed hot, the formability is improved. It has also been confirmed that this has further improved the equipment, making it easier to reduce the amount of equipment required, and that, for example, even when one-bath molding is adopted, the molding accuracy is extremely high.

This invention has been made based on the above knowledge, and is based on the following: ``A method for manufacturing a groove-shaped material having flanges on both ends of the web by performing hot groove rolling followed by roll forming. As shown in Fig. 1, the final cross-sectional shape after hot hole rolling is approximately W-shaped, with the web portion (1) protruding in the direction of extension of the flange (2) and curved. Both ends are shaped into a straight line by a length of 10 to 20 degrees at a central angle (α) centered on the extended intersection (0) of the outer surfaces of both flanges, and the web portion is flattened by subsequent roll forming processing. By forming, it is possible to stably manufacture channel-shaped materials with good shape accuracy at a low cost. Another feature is that the shape accuracy and manufacturing cost of the grooved material can be further improved by performing these roll forming processes hot.

Here, the molding material may be of course ordinary steel, stainless steel, titanium (including titanium alloys), etc., and the type thereof is not critical.

Furthermore, the pass schedule for hot hole rolling is not particularly limited; for example, there is no problem in adopting the schedule up to the i-shape shown in FIG. 7, but if possible, the pass schedule as shown in FIG. It is preferable to adopt a pass schedule in which the starting material is a flat bar material and to roll with a small number of passes. However, when using flat par as the starting material, a forming roller guide as shown in Figure 3 is installed on the inlet side of the rolling mill, and the widthwise central part of the material (3) is first preformed into a chevron shape. Therefore, it is recommended to introduce this into the rolling mill. This prevents the flange width from swinging out (left-right swinging of the material) and stably ensures accurate shape and dimensions, including the pin corners, even under light reduction with a total reduction rate of 50 to 60%. will be done.

In addition, the length of the straight portions on both sides of the web in the final cross-sectional shape in hot hole rolling is 10 at the center angle α in FIG.
The length is limited to ~20° because the length is 1 at the central angle α.
If it is less than 0°, the effect of providing a straight part in the web part will not be obtained and it will be difficult to stably secure an accurate final product shape.On the other hand, if the central angle α exceeds 20°, the web This is because the radius of curvature at the central portion in the width direction becomes smaller, resulting in an acute bent shape, which tends to remain even after roll forming, making it difficult to ensure the flatness of the web.

By the way, when roll forming is performed in multiple passes, for example as shown in Fig. 4, it is possible to form the form easily and reliably, but according to the method of the present invention, a straight single roller ("#30-roller" in Fig. 4) is used. As mentioned above, stable molding can be achieved even in one pass using only the mold.

When roll forming is performed hot, the deformation resistance of the material is reduced, so good formability can be ensured under light loads, and products with good shape accuracy that can be fully satisfied even with the above-mentioned one-pass forming can be produced. However, "hot" here refers to the temperature range normally adopted under this term (for example, 600°C for steel materials such as stainless steel).
At temperatures exceeding ℃ (preferably up to about 850℃),
In the case of titanium, it goes without saying that this means a temperature exceeding 500°C (preferably up to about 800°C).

As described above, the method for producing a channel-shaped material according to the present invention is characterized in that the final rolled cross-sectional shape in hot hole rolling before the roll forming step is such that the center of the web is curved and protrudes, and the following side portions are of a predetermined length. One of its major features is that it has a W-shape that is straight across and connects to the flange.
As a result, the shape of the web portion of the intermediate material for roll forming does not curve immediately from the corner of the bottle as in the previous proposal [see Fig. 8 (al)], and therefore the pin angle is a small corner that is difficult to recover. In addition, it is possible to significantly facilitate the flattening of the web portion by roll forming.
Hereinafter, the present invention will be specifically explained with reference to Examples.

<Example> After soaking a 5US304 stainless steel continuous casting billet with a mass of 125111 squares to 1250°C, it was passed through the 10th round (IR) and the 20th round (2R) according to the rolling schedule shown in Fig. 5. By doing so, rough rolling was performed to obtain a flat bar (K-6), which was then subjected to groove hot rolling according to the schedule shown in Fig. 5 to have a wall thickness of 5n and a center angle α of 13
An intermediate material (K-1) with a W-shaped cross section as shown in Figure 1 of
). In addition, the intermediate material temperature at this time is 830℃
Met.

Next, this intermediate material is continuously introduced as it is into a hot roll forming machine of the type shown in Figure 4, and the web portion is flattened to form a groove shape with parallel flanges and dimensions as shown in Figure 6. Got steel.

We investigated the quality of the channel steel obtained in this way, but
It was confirmed that the product was of good quality, with no rough skin or shape defects, and a perfect degree of pin angle filling.

In addition, apart from this, # in Figure 4 is used during hot roll forming.
5US under the same conditions as above except that only 30-ru was used.
A channel steel made of 304 stainless steel was manufactured, and it was confirmed that a good product could still be obtained.

Furthermore, a channel material was manufactured under the same conditions as above, except that T+-6Aβ-4 alloy was used as the material, the rolling heating temperature was 1000°C, and the 3-pass hot roll forming temperature was 650°C. A test was conducted and it was confirmed that a good product could be obtained in this case as well.

<Summary of Effects> As explained above, according to the present invention, it is possible to manufacture channel-shaped materials with good quality (surface texture, shape accuracy, etc.) with high efficiency and at low cost, regardless of the type of material. This brings about extremely useful effects in industry, such as making it possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing the final shape obtained by hot hole rolling according to the present invention. FIG. 2 is a drawing showing an example of a pass schedule for hot hole rolling according to the present invention. FIG. 3 is a schematic diagram showing an example of a forming roller guide disposed at the entrance of a rolling mill, which is suitable for carrying out the present invention using a flat bar as a raw material. FIG. 4 is an example of a pass schedule of a roll forming machine applied to the present invention. FIG. 5 is an explanatory diagram of the path schedule adopted in the example. FIG. 6 is a drawing showing the dimensions of each part of the channel-shaped member obtained in the example. FIG. 7 is a drawing showing an example of a pass schedule for conventional channel type steel rolling. Figure 8 shows an example of the final shape obtained by hot hole rolling prior to roll forming during the production of channel-shaped materials. In the drawings: 1...Web part, 2...Flange part. 3...Material. Applicant: Nippon Stainless Co., Ltd.

Claims (3)

[Claims] (1) When producing a channel material with flanges on both edges of the web by hot channel rolling followed by roll forming, the final cross-sectional shape of the hot channel rolling is The web part protrudes in the flange extension direction and is curved, almost W.
The flange-connected ends of the web are made straight by a length of 10 to 20° at a central angle centered on the extended intersection of the outer surfaces of both flanges, and then the web is formed by a subsequent roll forming process. A method for manufacturing a channel-shaped material, characterized by forming a portion flat. (2) The method for manufacturing a channel-shaped member according to claim 1, wherein the roll forming process for forming the web portion flatly is completed in one pass. (3) The method for producing a grooved material according to claim 1 or 2, wherein the roll forming process is carried out hot.