JP2833042B2 - Manufacturing method of metal expansion anchor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the invention]

(Field of Industrial Application) The present invention relates to a method for manufacturing a metal expansion anchor used for manufacturing an anchor used for retrofitting a plate, hardware, or the like to a base material such as concrete. (Prior art) Conventionally, when electrical construction work, plumbing work, air-conditioning duct work, plant construction, shelf installation work, hardware installation work, etc. are performed after concrete or the like has been constructed, metal materials are added to the base material of concrete or the like. When you add
A metal anchor body having an extension is inserted into a preformed hole, and then the extension is opened to use a metal extension anchor which cuts into a concrete hole wall. As this kind of metal expansion anchor, a cone adoption type such as a cone driving type or a body driving type combining a cone and an anchor body having an expansion portion expanded by the cone, or expanded by driving a core rod There is a core rod driving type in which an anchor body having an extension portion and a core rod are combined. Conventionally, when manufacturing this kind of metal expansion anchor, in the case of a cone adoption type, using an austenitic stainless steel as its material, an anchor body having an expansion portion expanded by a cone by performing a cutting process is used. It is molded and combined with a cone that expands the expansion portion, and the cone is driven (in the case of a cone driving type) or the anchor body is driven (in the case of a main body driving type), and the anchor is driven by the cone. The anchor body is fixed to concrete by expanding the extension part of the main body and biting into the concrete hole wall, and plates and hardware etc. are attached to this anchor main body,
Bolts and screws were screwed into the anchor body. In the core rod driving type, an austenitic stainless steel is used as a material thereof, and an anchor body having an expansion part expanded by driving the core rod is formed by performing a cutting process, and the expansion part is formed. The anchor body is fixed to concrete by being combined with a core rod to be expanded, and the expansion part of the anchor body is expanded and driven into the expanded concrete hole wall by driving of the core rod, thereby fixing the anchor body to concrete. And the like, and bolts and screws were screwed into the anchor body. (Problems to be Solved by the Invention) However, in the conventional metal expansion anchor, austenitic stainless steel is used as the material of the anchor body, so that the cost is high and the productivity is inferior because it is formed by cutting. And also the material yield is not good. (Object of the Invention) The present invention has been made in view of such conventional problems, and is less expensive than austenitic stainless steel as a material of the anchor body of the metal expansion anchor, and has a low cold workability, toughness, and a high durability. Use ferritic stainless steel with a specific component composition that has superior rust resistance, and increase the productivity by manufacturing the anchor body by forging using the superior cold workability of this ferritic stainless steel material. At the same time, by improving the material yield, the cost is reduced not only from the material side but also from the manufacturing side, and the superior toughness and rust resistance increase the pulling force of the anchor from the base material such as concrete and corrode. Manufacture of metal expansion anchors such as cone adoption type and core rod driving type that can prevent rust and rust generation for a long time It is intended to provide a fabrication method.

Configuration of the Invention

(Means for Solving the Problems) The method for producing a metal expansion anchor according to the present invention is as follows: C: less than 0.020%, Si: 0.50% or less, Mn: 0.50% or less, P: 0.030% or less, : 0.010% or less (when not contained as a machinability improving element), Cr: 16.0 to 25.0%, Cu: 0.05 to
2.0%, Ni: 0.05-2.0%, O: 0.010% or less, N: 0.025% or less, and if necessary, N as a crystal grain refining element group
b: 0.02-1.0%, Ta: 0.02-1.0%, V: 0.03-0.5%, Ti: 0.03
0.5%, Zr: one or more of 0.03 to 0.5%,
Mo: 0.05-3.0%, Co: 0.5-5.0% as a group of elements for improving corrosion resistance
One or two of these, S: 0.00 as a group of machinability improving elements
7 to 0.15%, Se: 0.010 to 0.15%, Pb: 0.03 to 0.35%, Ca: 0.00
1 to 0.03%, Bi: 0.005 to 0.20% At least one of each group of at least one of two or more groups, and the first ferrite stainless steel material containing the balance of Fe and impurities,
After hot rolling is performed as a process, a secondary process involving plastic working and heat treatment is performed as a second process to form a forged material, and as a third process, a forging process is performed on the forged material, and then as a fourth process, a machine is formed. By adding processing, it is characterized in that it is configured to obtain an anchor body having an expanded portion that is expanded by driving of a core rod or cone, etc. It is a means to solve the problem. Next, the reason for limiting the component composition (% by weight) of the ferritic stainless steel used in the method for manufacturing a metal expansion anchor according to the present invention will be described. C: less than 0.020% C is Nb, Ti, Zr added in impurities or added as necessary
In addition to forming carbides by combining with carbide-forming elements such as, the precipitated carbides may be the starting point of rust and reduce the rust and corrosion resistance, and also form carbides by combining with Nb etc. Is reduced to less than 0.020%, since the effect of addition of manganese decreases the toughness. Si: 0.50% or less Si has a deoxidizing action during steel melting,
Although it has the effect of increasing the oxidation resistance, the content of a large amount deteriorates the cold workability and toughness. Mn: 0.50% or less Mn has a deoxidizing and desulfurizing action when smelting steel, and also has an action to improve mechanical properties.However, if contained in a large amount, cold workability is impaired. 0.50% or less. P: 0.30% or less P must be reduced as much as possible because it reduces the cold workability of ferritic stainless steel.
It was as follows. S: 0.010% or less S tends to reduce the cold workability of ferritic stainless steel.
Although it is desirable that the content is not more than 010%, it is also an element having an effect of improving machinability. Therefore, when such an effect of improving machinability is obtained, it can be positively added as described later. Cr: 16.0 to 25.0% Cr is a basic element of ferritic stainless steel, and is set to 16.0% or more in order to obtain sufficient corrosion resistance. However, if contained in a large amount, the cold workability is reduced and the toughness is deteriorated. Cu: 0.05 ~ 2.0% Ni: 0.05 ~ 2.0% Cu, Ni is an effective element to further improve the corrosion resistance of ferritic stainless steel. It is effective to contain 0.05% or more for Cu and 0.05% or more for Ni. However, since these large additions affect the cold workability and toughness, Cu is less than 2.0% and Ni is less than 2.0%.
Must be 2.0% or less. O: 0.010% or less O forms an oxide in combination with various elements, and adversely affects cold workability, rust resistance, and corrosion resistance. N: 0.025% or less N is Nb, Ti, Zr added in impurities or as necessary
Combines with nitride-forming elements such as to form nitrides, and the precipitated nitrides may act as starting points for rust, deteriorating rust and corrosion resistance, and combine with Nb to form nitrides By doing so, the effect of adding them is reduced and the toughness is degraded, so the content was made 0.025% or less. Nb: 0.02 to 1.0%, Ta: 0.02 to 1.0%, V: 0.03 to 0.5%, Ti: 0.0
3 to 0.5%, Zr: one or more of 0.03 to 0.5% Nb, Ta, V, Ti, Zr are a group of crystal grain refinement elements, which refine crystal grains to improve toughness, It is effective for improving cold workability, and also contributes to improvement of corrosion resistance. To obtain these effects, Nb is 0.02% or more, Ta is 0.02% or more, V is 0.03% or more, Ti is 0.03% or more, Zr
It is also possible to add one or two or more if necessary, but if contained in a large amount, the toughness is rather deteriorated. Therefore, even if added, Nb is 1.0% or less, Ta is 1.0% or less, and V is 0.5% or less. %, Ti must be 0.5% or less, and Zr must be 0.5% or less. Mo: 0.05 to 3.0%, Co: 0.5 to 5.0%, one or two of them Mo and Co are a group of elements for improving corrosion resistance, and further improve the durability in a base material such as concrete by improving corrosion resistance. It is effective to assume. And in order to obtain such an effect, Mo should be 0.05% or more and Co should be 0.5%.
One or two or more may be contained as necessary, but if contained in a large amount, the cold workability and toughness are adversely affected.
% Or less. S: 0.007 to 15%, Se: 0.010 to 0.15%, Pb: 0.03 to 0.35%, Ca: 0.001 to 0.03%, Bi: 0.005 to 0.20% One or more of S, Se, Pb, Ca , Bi are machinability improving elements,
This is effective for improving machinability and improving finishing by machining. In order to obtain such effects, S is 0.007% or more, Se is 0.010% or more, and Pb is 0.03%.
More than 0.001% of Ca and more than 0.005% of Bi
It is also possible to contain one or more species, but if it is contained in a large amount, the cold workability is degraded, so even if added, S is 0.15% or less, Se is 0.15% or less, Pb is 0.35% or less, It is necessary to make Ca less than 0.03% and Bi less than 0.20%. Then, when obtaining a forged material from such a ferritic stainless steel material, a steel material having the above-described composition is subjected to hot rolling as a first step. In this hot rolling, it is particularly desirable to perform hot working with a working ratio of 80% or more at a temperature of 1000 ° C. or less. This is because, by performing rolling at a temperature of 1000 ° C. at a temperature of 1000 ° C. and a rolling ratio (reduction rate) of 80% or more during hot rolling, ie, wire rod rolling, it becomes possible to further improve toughness. After this hot rolling, 2
A forging material having a predetermined diameter is obtained by performing the subsequent processing. FIG. 1 exemplifies the results of examining the effects on the toughness (impact value) by the wire rolling heating temperature, the working temperature and the working rate (reduction rate) during wire rolling. I
Is a wire rod heating temperature of 1200 ° C and a processing rate (area reduction rate) at a temperature of 1000 ° C or less is 0%. Wire II is a wire rod heating temperature of 1050 ° C and a processing rate at a temperature of 1000 ° C or less. Pressure (area reduction rate) is 80%, and wire III has a material rolling heating temperature of 1000
℃ and the processing rate (reduction rate) at a temperature of 1000 ℃ or less
%, The results are shown in the case of performing hot rolling at 850 ° C., then annealing at 850 ° C., and then conducting a Charpy impact test. As shown in FIG. 1, by performing hot working at a temperature of 1000 ° C. or less at a working rate (reduction rate) of 80% or more at the time of wire rolling, the transition temperature of the Charpy impact value is lowered and the toughness is remarkably increased. It is clear that it will improve. After performing the hot rolling in the first step, a forging material is obtained by performing a secondary processing involving plastic working and heat treatment as a second step. In this secondary processing,
It is also desirable, if necessary, to select from the following exemplary embodiments and appropriately adopt them. In one embodiment, in the secondary processing as the second step, after the primary processing rate of 25% or more is added, 700 to 8
A heat treatment is performed at a temperature of 50 ° C. that does not cause recrystallization, a coating treatment is applied, and a finish drawing with a surface reduction rate of 10% or less is performed to obtain a forging material. In this case, the primary processing coverage is set to 25% or more to achieve the necessary crystal grain refinement, and the heat treatment is performed at a temperature of 700 to 850 ° C that does not recrystallize, so that the strength is suitable for the next step of forging. And you will be able to Then, when performing the coating treatment after performing such a heat treatment, a oxalate film or a different resin coating is formed to prevent galling in the next step of forging, And to improve the life of the mold. Further, after applying this coating treatment, it is desirable to perform finish wire drawing with a reduction in area of 10% or less so that the adhesion of the coating on the surface of the forged material is further improved. 10% reduction in area during wire drawing
If it is larger than this, the strength is increased and the formability in the next step is reduced. Therefore, it is desirable that the area reduction rate is 10% or less. On the other hand, in another embodiment of the secondary processing as the second step, after a processing of a primary processing rate of 30% is added, 950 to 110 is applied.
A heat treatment is performed at a temperature of recrystallization of 0 ° C., a coating treatment is performed, and a finish drawing with a surface reduction rate of 10% or less is performed to produce a forging material. In this case, it is possible to recrystallize in the subsequent heat treatment by making the primary processing rate 30% or more of the strong processing, and the toughness is improved by performing the heat treatment at a temperature of 950 to 1100 ° C for recrystallization. It will be possible to do it. At this time, if the heat treatment temperature is too high, the crystal grains are coarsened, so that the temperature is desirably 1100 ° C. or less. Then, when performing the coating treatment after performing such a heat treatment, an oxalic acid coating or a resin coating is formed in the same manner as in the above embodiment, and galling occurs in the next step of forging, It is possible to improve the metal life at the time of processing, and after performing this coating treatment, finish reduction with a surface reduction rate of 10% or less is performed as in the above embodiment to obtain a forged material. . After the forged material is obtained in the second step, the forged material is subjected to forging (forward extrusion, backward extrusion, etc.) as the third step to obtain a molded anchor body. In this case, it is possible to further improve the toughness of the anchor body molded product by such a forging process.
For example, when a cold-rolled material having a characteristic shown in line III of FIG. 1 subjected to hot working of 95% and having a cross-sectional reduction rate of 50% is applied to the forged material, the line IV in FIG. As shown by the broken line, the toughness is further improved. Next, a mechanical process (e.g., pleating, knurling, tapping, milling, etc.) is added to the thus obtained molded anchor body as a fourth step, thereby expanding the core rod by driving. To obtain an unsurfaced anchor body having a portion. Further, if necessary, a surface treatment for improving rust resistance is performed on the unsurfaced anchor body as a fifth step.
As this surface treatment, for example, 10 to 50% nitric acid (HN
Passivation treatment using an aqueous solution containing O ₃ ) and 0.2 to 5% sodium bichromate (Na ₂ Cr ₂ O ₇ ) at a temperature of 25 to 90 ° C. for 5 to 60 minutes can be performed. it can. The thus obtained unsurfaced or surface-treated anchor body is used in combination with a cone or a core rod, and is used to drive the anchor body (in the case of a main body driven type metal expansion anchor) and to drive the cone (internally). In the case of a cone driving type metal expansion anchor), the expansion portion is fixed by driving a core rod into the anchor main body to bite into a wall surface of a hole formed in concrete in advance. (Example) Example 1 This Example 1 shows an example in which an internal cone driving type metal expansion anchor for driving an internal cone is manufactured. Various stainless steel materials of scientific composition shown in Table 1
The steel wire was heated to ℃ and forged to a diameter of 60 mm, and further rolled to obtain a steel wire, which was annealed at 850 ° C. Next, for each of the above-mentioned steel wire rods, the heating rate (area reduction rate) at a temperature of 1000 ° C. or less was set to the value shown in Table 1 with the wire rolling heating temperature also being the value shown in Table 1. When hot working is performed under the hot rolling conditions, and then secondary working is performed on each rolled wire, the primary wire drawing rate, heat treatment temperature, coating treatment, and area reduction rate also shown in Table 1 are applied.
By performing secondary processing with a finish wire drawing of 10% or less, a wire drawn material having a diameter of 11.6 mm was obtained. Next, after cutting the drawn wire except Nos. 1 and 2 in Table 1 to obtain the forged material 1 shown in FIG. 2, the forged body 2 in the first step shown in FIG. Further, the formed anchor main body 3 shown in FIG. 3 (b) was obtained by performing the forging process of 3 to 5 steps. At this time, the cross-sectional reduction rate (d ² /) expressed by the outer diameter D and the inner diameter d of the molded anchor body 3
It has been found that it is better to set D ² ) × 100 (%) to about 35 to 60%. In addition, length L and inner diameter d
It has been found that it is even better to make the major axis ratio (L / d) expressed by the following formula: 2.5 to 3.5. And
The forging property of each material in this forging process was also the result shown in Table 1. Next, FIG. 4 (a) which is the same as that shown in FIG. 3 (b)
4 (b) with respect to the molded anchor body 3 shown in FIG.
The knurled portion 4a shown in FIG. 4 is formed by a rolling machine, the knurled portion 4b shown in FIG. 4 (c) is formed by a tapping machine, and the axial groove 4c shown in FIG. 4 (d). Milling process to form only four slices at 90 ° intervals in the circumferential direction,
An unsurfaced anchor body 5 was obtained. Next, for the unsurfaced anchor body 5 shown in FIG. 4 (d), degreasing using an alkaline degreasing bath → chemical polishing using a scientific abrasive → water washing → neutralization → using an alkaline abrasive Barrel polishing (which can also be said to be a physical polishing process and may be only one of the above-mentioned chemical polishing processes) → water washing → passivation process (350 cc / nitric acid, 3 g of sodium bichromate / temperature 50 ~ 60 ° C, time 60 minutes) → Washing →
By applying a passivation treatment through drying (provided that it is indicated as "Yes" in the passivation treatment column of Table 1), the extension is extended by the inner cone 6 as shown in FIG. A metal expansion anchor 8 with an internal cone adopting an internal cone, which is obtained by combining the surface-treated anchor body 7 having the portion 7a and the internal cone 6, is obtained. In the conventional examples 1 and 2, the metal expansion anchor (8) was obtained by cutting. The metal expansion anchor 8 obtained here has an outer diameter of 12.0 mm, a screw system of the screw portion receiver 4b of W3 / 8, a screw length of 15 mm, and a total length of 40 mm. Next, in order to evaluate the rust resistance of the surface-treated anchor body 7, a salt spray test (35 ° C., 5% N) according to JIS Z2371 was conducted.
aCl, 96 hours). The results are also shown in Table 1. In Table 1, ◎ indicates that the rust resistance was fairly good, ○ indicates that the rust resistance was good, and △ indicates that the rust resistance was too low. If it was not good, the cross indicates that the rust resistance was poor. The metal expansion anchor 8 employing the internal cone shown in FIG. 5 was previously drilled in a concrete wall with a drill hole having a diameter of 12.5 mm in this embodiment. Is inserted into the drilled hole, and the inner cone 6 is driven by a jig (not shown), whereby the expanded portion 7a of the anchor body 7 is expanded by the inner cone 6 and a concrete drill is formed. It is fixed by cutting into the hole wall. Then, after the concrete was poured into concrete having a concrete strength of 200 kgf / cm ² , the maximum pull-out strength was examined. The results are also shown in Table 1. As shown in Table 1, a conventional example manufactured by cutting from austenitic stainless steel (SUS304)
When the No. 1 anchor body is used, the maximum pull-out strength is good, but the productivity is poor due to the cutting process,
In addition, the material yield is low, and the material cost is high. In addition, when the anchor body of the conventional example No. 2 made of austenitic stainless steel (SUS303) by cutting is used, the rust resistance is high. The steel material of Comparative Example No. 3 also made of austenitic stainless steel (SUSXM7) was poor in forging performance, and the steel material of ferritic stainless steel (SUS430) was made by forging. When the anchor body of No. 4 is used, the rust resistance is not good, and when the anchor body of Comparative Example No. 5 which does not contain Cu and Ni in ferritic stainless steel is used, the rust resistance is poor. It was not very good. In contrast, an anchor body manufactured by applying forging and machining to a forging material made of ferritic stainless steel of a predetermined component has good forging properties during forging and has a high rust resistance. It is also recognized that the maximum pulling strength is large and the value of the maximum pulling strength is large. When hot working at a temperature of 1000 ° C or less and a working ratio of 80% or more is applied during the first step of hot rolling. The maximum pull-out strength can be further increased, and the maximum pull-out strength can be further increased by satisfying specific conditions in the secondary processing in the second step. It has been found that the rust resistance can be further improved by performing a passivation treatment for improving rust resistance as a fifth step after the machining in the fourth step. Embodiment 2 This embodiment 2 shows an example in which a body driving type metal expansion anchor for driving an anchor body is manufactured. Various stainless steel materials with the chemical components shown in Table 2
The steel wire was heated to ℃ and forged to a diameter of 60 mm, and further rolled to obtain a steel wire, which was annealed at 850 ° C. Next, for each of the above-mentioned steel wire rods, the heat treatment was performed such that the working rate (area reduction rate) at a temperature of 1000 ° C. or less was the value shown in Table 2 with the wire rolling heating temperature also being the value shown in Table 2. When hot working is performed under rolling conditions, and then applied to the secondary working of each rolled wire, the primary wire drawing rate, heat treatment temperature, coating treatment, and area reduction rate are also shown in Table 2.
By performing secondary processing by finish wire drawing of 10% or less, a drawn wire material having a diameter of 13.7 mm was obtained. Next, after cutting the drawn wire except Nos. 31 and 32 in Table 2 to obtain a forged material, the forged body 12 in the first step shown in FIG. 6 (a) and then FIG. Forged body shown in)
By further performing two to five steps of forging from 12 ', a molded anchor body 13 shown in FIG. 6 (c) was obtained. At this time, it is more preferable that the cross-sectional reduction rate (d ² / D ² ) × 100 (%) represented by the outer diameter D and the inner diameter d of the molded anchor body 13 is about 20 to 50%. It was recognized that.
In addition, the major axis ratio (L / d) represented by the length L and the internal diameter d is
It has been found that it is better to set the value to about 2.5 to 3.5. The forging property of each material in this forging process was also the result shown in Table 2. Next, a shirring process 14a shown in FIG. 7 (b) is formed by an automatic lathe on the molded anchor body 13 shown in FIG. 7 (a) shown in FIG. 6 (c). Shirring, tapping to form the screw portion 14b shown in FIG. 7 (c) with a tapping machine, and only four axial grooves 14c shown in FIG. 7 (d) at 90 ° intervals in the circumferential direction. By performing a milling process using a slicer, an unsurfaced anchor main body 15 was obtained. Next, the unsurfaced anchor body shown in FIG.
In contrast to the above, degreasing using an alkaline degreasing bath, chemical polishing using a chemical abrasive, washing with water, neutralization, barrel polishing using an alkaline abrasive (also referred to as physical polishing, Either one of them may be used.) → Washing → Passivation treatment (350cc / nitric acid, 3g / sodium dichromate /, temperature 50-60 ° C, time 60 minutes) → Washing →
By applying a passivation treatment through drying (provided that it is indicated as "present" in the passivation treatment column of Table 2), the extension portion extended by the cone 16 as shown in FIG. An anchor body 17 having 17a and the cone 16
In this way, a metal-equipped metal-expandable anchor 18 employing a cone was obtained. In the conventional examples 31 and 32, the metal expansion anchor (18) was obtained by cutting. The metal expansion anchor 18 obtained here has an outer diameter of 14.0 mm, a screw diameter of the screw portion 14b of 8.0 mm, a screw length of 15 mm, and a total length of 40 mm. Next, in order to evaluate the rust resistance of the surface-treated anchor body 17, the same salt spray test as in Example 1 was performed. The results are also shown in Table 2. The cone-type metal expansion anchor 18 shown in FIG.
In this example, the diameter is 14.5 in advance on the concrete wall.
mm, the anchor body 17 is inserted into the drill hole, and the anchor body 17 is driven by a jig (not shown).
The expansion portion 17a of the expansion 17 is fixed by being expanded and biting into the concrete drill hole wall surface. Then, when the maximum pull-out strength after being poured into concrete having a concrete strength of 200 kgf / cm ² was examined, the results are also shown in Table 2. As shown in Table 2, in Example 2, the anchor body 17 of the present invention also has good forgeability in the forging process after the forging process, excellent rust resistance, and the anchor body 17 and the cone 16 The maximum pull-out strength in a state where the metal expansion anchor 18 combined with
When hot working with a working ratio of 80% or more is applied at a temperature of ℃ or less, the maximum pulling strength can be further increased, and the specific conditions are satisfied in the secondary processing of the second step. It is possible to further increase the maximum pull-out strength by performing the passivation treatment. After the machining in the fourth step, a passivation treatment for improving the rust resistance is performed in the fifth step to improve the rust resistance. It was recognized that it could be further improved. Embodiment 3 This embodiment 3 shows an example in which a core rod driving type metal expansion anchor is manufactured. Various stainless steel materials with the chemical components shown in Table 3
The steel wire was heated to ℃ and forged to a diameter of 60 mm, and further rolled to obtain a steel wire, which was annealed at 850 ° C. Next, for each of the above-mentioned steel wire rods, a heat-sensitive material was used such that the working rate (area reduction rate) at a temperature of 1000 ° C. or less was also the value shown in Table 3 with the wire rolling heating temperature shown in Table 3. When hot working is performed under rolling conditions, and then each rolled wire is subjected to secondary working, the primary wire drawing rate, heat treatment temperature, coating treatment, and surface reduction rate are also shown in Table 3.
A secondary wire with a finish wire drawing of 10% or less was added to obtain a drawn wire having a diameter of 4.88 mm. Next, after cutting the drawn wire except Nos. 61 and 62 in Table 3 to obtain the forged material 21 shown in FIG. 9, the forged body 22 in the first step shown in FIG. By performing several steps of forging, a molded anchor main body 23 shown in FIG. 10 (b) was obtained. At this time, the anchor body molded product 23
Reduction rate (d ² / D ² ) expressed by outer diameter D and inner diameter d
X100 (%) was found to be even better to be about 15 to 45%. It was also found that the ratio of the long diameter (L / d) represented by the length L and the inner diameter d was more preferably about 6 to 12. The forging property of each material in this forging process was also the result shown in Table 3. Next, the same FIG. 11 (a) as shown in FIG. 10 (b)
11 (b) with respect to the molded anchor body 23 shown in FIG.
In FIG. 11 (c), an axial groove 24b shown in FIG.
未 An unsurfaced anchor main body 25 was obtained by performing milling processing in which only two pieces were formed by a slicer at intervals. Next, the unsurfaced anchor body shown in FIG.
For 25, degreasing using an alkaline degreasing bath → polishing for each amount using a chemical abrasive → washing with water → neutralization → barrel polishing using an alkaline abrasive (also referred to as physical polishing, Or water passivation treatment (350 cc of nitric acid, 3 g of sodium bichromate, temperature 50-60 ° C, time 60 minutes) → water passivation → passivation through drying By performing the process (however, the process is performed on those indicated as “Yes” in the passivation process column of Table 3), the core is extended by the core rod 26 having the internal tapered portion 26a as shown in FIG. A core rod driving type metal expansion anchor 28 obtained by combining the surface-treated anchor main body 27 having the expansion part 27a and the core rod 26 was obtained. Conventional examples 1 and 2
In, a metal expansion anchor (28) was obtained by cutting. The metal expansion anchor body 27 obtained here has an outer diameter of 5.
It is 0mm, the head diameter is 9.0mm, and the total length under the neck is 30mm. Next, in order to evaluate the rust resistance of the surface-treated anchor body 27, a salt spray test (35 ° C, 5 ° C) in accordance with JIS Z2371 was conducted.
% NaCl, 96 hours). The results are also shown in Table 3. In Table 3, ◎ indicates that the rust resistance was quite good, ○ indicates that the rust resistance was good, and △ indicates that the rust resistance was very good. However, the crosses indicate that the rust resistance was poor. Core rod driving type metal expansion anchor 28 shown in FIG.
In this example, the diameter is
In a mode in which a 5.4 mm drill hole was formed, the core rod 26 was inserted into the drill hole and the head 26b was inserted by a jig (not shown).
Is driven toward the top of the anchor body 27, and the delicate portion 26a of the
The extension 27a is expanded and cut into the concrete drill hole wall surface to be fixed. Then, after the concrete was poured into concrete having a concrete strength of 200 kgf / cm ² , the maximum pull-out strength was examined. The results are also shown in Table 3. As shown in Table 3, a conventional example manufactured by cutting from austenitic stainless steel (SUS304)
When the anchor body of No. 61 is used, although the maximum pull-out strength is good, the productivity is poor due to the cutting process, the material yield is low, and the material cost is high, and the austenitic material is also used. In the case of using the anchor body of the conventional example No. 62 manufactured by cutting stainless steel (SUS303) as a material, the rust resistance is slightly inferior, and the austenitic stainless steel (SUSXM
The steel material of Comparative Example No. 63 made of 7) has poor forging properties, and the anchor body of Comparative Example No. 64 made of ferritic stainless steel (SUS430) by forging is resistant. Comparative example No.65 which does not have good rust and does not contain Cu and Ni in ferritic stainless steel
When the anchor body was used, the rust resistance was not so good. In contrast, the anchor body manufactured by forging and machining a forged material made of a ferritic stainless steel of the specified component has good forging properties in the forging process, and has high rust resistance. It is also recognized that the maximum pulling strength is large and the value of the maximum pulling strength is large. When hot working at a temperature of 1000 ° C or less and a working ratio of 80% or more is applied during the first step of hot rolling. It is possible to further increase the maximum pull-out strength by satisfying specific conditions also in the secondary process of the second processing, it is possible to further increase the maximum pull-out strength, It was recognized that the rust resistance can be further improved by performing a passivation treatment for improving the rust resistance as the fifth step after the machining in the fourth step. Example 4 In this example, a predetermined hot rolling heating temperature, a working rate at a temperature of 1000 ° C. or less, a primary drawing rate in secondary working,
As shown in FIG. 13, a rolling process for forming a shallow mountain processed portion 34a with a rolling machine is performed on a molded anchor body obtained by performing a heat treatment temperature, a coating process, a forging process, and the like.
By performing tapping for forming the threaded portion 34c with a tapping disk and reaming for forming only four axial grooves 34b at intervals of 90 ° in the circumferential direction with a sliced disk, the unsurfaced anchor body 35 is formed. Then, passivation treatment is applied to the untreated surface anchor body 35 as necessary, so that the tapered portion as shown in FIG. 14 is obtained.
FIG. 14 shows a case in which a core rod driving type metal expansion anchor 38 is obtained by combining a surface-treated anchor body 37 having an extension portion 37a expanded by a core rod 36 having the core 36 and the core rod 36. The anchor body 37 having the shape shown in FIG. 1 also has good forging property during forging, excellent rust resistance, and the anchor body 37 and the core rod.
The maximum pull-out strength in a state where the metal expansion anchor 38 in combination with 36 was driven into concrete also showed a large value.

【The invention's effect】

The manufacturing method of the metal expansion anchor according to the present invention is as follows: C: less than 0.020%, Si: 0.50% or less, Mn: 0.50% or less, P: 0.030% or less, S: 0.010% or less, When not contained as an improving element), Cr: 16.0-25.0%, Cu: 0.05-
2.0%, Ni: 0.05-2.0%, O: 0.010% or less, N: 0.025% or less, and if necessary, N as a crystal grain refining element group
b: 0.02-1.0%, Ta: 0.02-1.0%, V: 0.03-0.5%, Ti: 0.03
0.5%, Zr: one or more of 0.03 to 0.5%,
Mo: 0.05-3.0%, Co: 0.5-5.0% as a group of elements for improving corrosion resistance
One or two of these, S: 0.00 as a group of machinability improving elements
7 to 0.15%, Se: 0.010 to 0.15%, Pb: 0.03 to 0.35%, Ca: 0.00
1 to 0.03%, Bi: 0.005 to 0.20% At least one of each group of at least one of two or more groups, and the first ferrite stainless steel material containing the balance of Fe and impurities,
After hot rolling is performed as a process, a secondary process involving plastic working and heat treatment is performed as a second process to form a forged material, and as a third process, a forging process is performed on the forged material, and then as a fourth process, a machine is formed. By adding processing, an anchor body having an expanded portion that is expanded by driving of a core rod or a cone is obtained, so that the productivity is remarkably improved by forming by forging, and the material yield is remarkably good. As a result, it is possible to reduce the cost from the manufacturing side, it is possible to prevent the generation of rust due to its excellent rust resistance, and it is extremely excellent in the maximum pull-out strength after retrofitting to concrete wall etc. It is possible to reduce the cost from the surface material as compared with the case of using the conventional austenitic stainless steel. Leads to significantly better effect.

[Brief description of the drawings]

FIG. 1 is a graph illustrating the results of examining the effect on the toughness (impact value) of the wire rod heating temperature, the processing temperature and the processing rate (reduction rate) during wire rod rolling, and FIG. 2 is an example of the present invention. 1
FIG. 3 (a) and FIG. 3 (b) are cross-sectional views showing the shape of the forged body at the beginning and at the end of the forging process of Example 1, and FIG. 4 (a). )
(B), (c), and (d) are cutaway front views of the left half of the anchor main body at the time of each finishing process of the first embodiment, and FIG.
6 (a), 6 (b), and 6 (c) are front views of a left-half cutaway metal-expandable metal-expandable-type metal-equipped anchor of the second embodiment. FIG. 7 (a) is a cross-sectional view showing the shape of FIG.
(B), (c), and (d) are front cutaway views of the left half of the anchor main body at the time of each finishing process of the second embodiment, and FIG.
9 is a cutaway front view of a left half of a metal-expandable anchor that adopts a cone adopting a cone, FIG. 9 is a cross-sectional view of the forging material used in Embodiment 3 of the present invention, FIG. 10 (a) and FIG. 10 (b).
FIG. 11 is a cross-sectional view showing the shape of the forged body at the beginning of forging and at the end of forging of Example 3, and FIGS. 11 (a) and 11 (b).
(C) is a left-half cutaway front view of the anchor main body at the time of each finishing work of Example 3, FIG. 12 is a left-half cutaway front view of the core rod driving type metal expansion anchor of Example 3, and FIG. 13 is an example. FIG. 14 is a left half cutaway front view of a left half of the anchor body of Example 4, and FIG. 5,15… untreated surface anchor body, 6,16… cone, 7,17… surface treated anchor body, 7a, 17a… cone extension, 8,18… cone adoption type metal extension anchor , 25,35… untreated surface anchor body, 26, 36… core rod, 27, 37… surface treated anchor body, 27a, 37a… expanded part by driving core rod, 28, 38… core Rod driven metal expansion anchor.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-142054 (JP, A) JP-A-54-158364 (JP, A) JP-A-3-90515 (JP, A) JP-A-3-1990 90242 (JP, A) JP-A-1-201445 (JP, A) JP-A-1-122104 (JP, U) JP-A-57-71609 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) C21D 8/06 B21K 1/74 C22C 38/00-38/60

Claims (6)

(57) [Claims] (1) By weight%, C: less than 0.020%, Si: 0.50% or less, Mn: 0.50% or less, P: 0.030% or less, S: 0.010% or less, C:
r: 16.0-25.0%, Cu: 0.05-2.0%, Ni: 0.05-2.0%, O:
0.010% or less, N: 0.025% or less, ferritic stainless steel material consisting of balance of Fe and impurities, hot-rolled as a first step, followed by plastic processing and secondary processing with heat treatment as a second step A method for producing a metal-expanded anchor, comprising: obtaining a forged material; performing a forging process on the forged material as a third step; and performing a machining process as a fourth step to obtain an anchor body. 2. In% by weight, C: less than 0.020%, Si: 0.50% or less, Mn: 0.50% or less, P: 0.030% or less, S: 0.010% or less,
(When not contained as a machinability improving element), Cr: 16.0-2
5.0%, Cu: 0.05-2.0%, Ni: 0.05-2.0%, O: 0.010% or less, N: 0.025% or less, and N as a grain refinement element group
b: 0.02-1.0%, Ta: 0.02-1.0%, V: 0.03-0.5%, Ti: 0.03
~ 0.5%, Zr: one or more of 0.03 ~ 0.5%,
Mo: 0.05-3.0%, Co: 0.5-5.0% as a group of elements for improving corrosion resistance
One or two of these, S: 0.
007-0.15%, Se: 0.010-0.15%, Pb: 0.03-0.35%, Ca: 0.
001-0.03%, Bi: 0.005-0.20% Ferrite-based stainless steel material containing at least one of one or more of each group of 0.005 to 0.20%, the balance being Fe and impurities After the cold rolling, a secondary process involving plastic working and heat treatment is added as a second step to form a forged material, and as a third step, the forged material is added to the forged material, and then a machining is performed as a fourth step. A method for manufacturing a metal expanded anchor, characterized in that an anchor body is obtained. 3. The metal expansion anchor according to claim 1, wherein in the hot rolling in the first step, hot working is performed at a temperature of 1000 ° C. or less and a working rate of 80% or more. Manufacturing method. 4. A process involving plastic working and heat treatment in a second step.
In the subsequent processing, after the processing of the primary processing rate of 25% or more, heat treatment at a temperature of 700 to 850 ° C that does not recrystallize,
The method for producing a metal expansion anchor according to any one of claims (1) to (3), wherein after the coating treatment is performed, a finish drawing with a surface reduction rate of 10% or less is performed to obtain a forged material. 5. The method according to claim 2, wherein the second step involves plastic working and heat treatment.
In the next processing, after the processing of the primary processing rate 30% or more, heat treatment at a temperature of 950 to 1100 ° C for recrystallization,
The method for producing a metal expansion anchor according to any one of claims (1) to (3), wherein after the coating treatment is performed, a finish drawing with a surface reduction rate of 10% or less is performed to obtain a forged material. 6. The method according to claim 1, wherein after the machining in the fourth step, a surface treatment for improving rust resistance is performed on the surface of the anchor body as a fifth step. 3. The method for producing a metal expansion anchor according to item 1.