TW200927956A - Two-phase stainless steel wire rod, steel wire, bolt and manufacturing method thereof - Google Patents

Abstract

This high cold forgeability austenitic-ferritic two phase steel wire rood used for bolts of high mechanical strength and high corrosion resistant includes, C of 0. 005 to 0. 05 mass%, Si of 0. 1 to 1. 0 mass%, Mn of 0. 1 to 10. 0 mass%, Ni of 1. 0 to 6. 0 mass%, Cr of 19. 0 to 30. 0 mass%, Cu of 0. 05 to 3. 0 mass%, N of 0. 005 to 0. 20 mass% and a balance of Fe and inevitable impurities. In this steel, C+N are 0. 20 mass% or less, the M value of the following formula (a) is less than 60, the F value of the following formula (b) is 45 to 85, and the tensile strength is 550 to 750 N/mm<SP>2</SP>. M=551-462 (C+N)-9. 2Si-8. 1Mn-29 (Ni+Cu)-13. 7Cr-18. 5Mo. . . (a) F=5. 6Cr-7. 1Ni+2. 4Mo+15Si-3. 1Mn-300C-134N-26. 6. . . (b)

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual-phase unrecorded steel wire excellent in cold forgeability, and is provided at a price of 5 grids, such as having a corrosion resistance equivalent to SUS3〇4. High strength screws. The present invention relates to a soft two-phase steel wire having a magnetization property excellent in cold workability, and is provided with a bolt, a pin, a wire mesh, a metal wire, and the like, which are equivalently provided with corrosion resistance equivalent to SUS304 and SUS316. A strong cold-worked member such as a rope or a spring, and a soft duplex stainless steel wire excellent in cold workability of magnetization. This application is based on the special wish 2〇〇7 — 264992 of Sakamoto, and the special wish of 2〇〇7_ 264993, which was submitted in Japan on the 1st of January, 2007. Claim priority and use its content for this. 15 【】

Background of the Invention As far as the high-strength, high-resistance residual screw of the strength of 700 N/mm2 is concerned, SUS304 wire is widely used. However, in recent years, the strength of the screw that is required to be further improved (lightweight) has been demanded in the field of cars and home appliances. Further, since the SUS304 screw is expensive because it contains a large amount of expensive Ni raw material, it is also strongly required to be reduced in cost. Heretofore, the high-strength of the screw is associated with a SUS630 screw of a granulated iron-based non-scale steel (for example, Patent Document 1). However, although the SUS630 screw is excellent in strength, the corrosion resistance is not only 20, 2009, and the cold forgeability is remarkably inferior, so the manufacturing cost is greatly increased and the use is extremely limited. Further, there has been proposed a high-strength screw made of 麻田散铁-based stainless steel of about 13% Cr which is excellent in manufacturability and low in cost (Patent Document 52). However, 'corrosion resistance is not enough, and the use is limited. Further, a high-strength screw made of a high (C + Ν) amount of Vostian iron-based stainless steel has been proposed (Patent Document 3). However, due to the poor cold forging property, the manufacturing cost is greatly increased without being accepted by the market. On the other hand, in recent years, there has been proposed an inexpensive duplex stainless steel (Patent Documents 4 to 6) which suppresses the high-priced and low-cost 10 series. However, the conventional duplex stainless steel has poor cold forgeability and high manufacturing cost, and the duplex stainless steel screw is no longer present in the market. As described above, in the stainless steel wire for stainless steel screws and screws, there are no products having high corrosion resistance, high strength, high cold forgeability, and low cost. 15 For products such as bolts, pins, wire mesh, and metal wires that require corrosion resistance, use Worstian iron-based stainless steel wires such as SUS304 and SUSXM7, and perform cold-cooling processing such as drawing or cold forging or bending. Manufacturing. In the cold working of the wire, the difference in the stamping property of the steel sheet having the high tensile properties of the required material requires a soft and high tensile fracture elongation characteristic (the high elongation property is not required). The soft material is required to have a tensile strength of the wire of 700 N/mm 2 or less and is preferably 650 N/mm 2 or less. However, the Worthfield iron-based stainless steel product has a high price of Ni, so there are still disadvantages of high product prices despite the low-cost process. In addition, the Inversity Iron-based stainless steel is non-magnetic, and the fastener is locked in 200927956. It cannot be attached to the tool during operation, resulting in poor workability, and the wire mesh, the screen (especially the conveyor belt for food, etc.) are mixed due to the material falling off. In the case of food, there is an inconvenience caused by the non-magnetic property due to the inability to detect the incorporation by the magnetic sensor. 5 ❹ 10 15 ❿ For products requiring magnetic and corrosion resistance, a ferrite-based stainless steel wire made of ferrite-iron-iron stainless steel wire, low C, N and added with Nb is proposed (Patent Documents 7 to 9) ). However, not only the corrosion resistance of the cold-worked product is insufficient, but also the surface defects are generated when the high-Cr-based wire is rolled, and the manufacturing cost is increased. On the other hand, in recent years, a duplex stainless steel having a low cost of Ni has been proposed (Patent Documents 10 to 12). Patent Document 10 describes a high-strength duplex stainless steel having a low Ni-based and excellent Young's modulus of 0.04% or more of nitrogen having improved strength. However, Si is added in an amount of more than 1% and nitrogen is added in an amount of 0.04% or more, and in the examples, high-strength steel exceeding 80 kg/mm 2 is described, and there is no consideration of soft and high tensile fracture elongation characteristics. The cold workability of the wire is not good. Patent Document 11 describes a duplex stainless steel having a low visibility system and containing a corrosion resistance of 5% or more of nitrogen and good weldability. However, there is no description of the cold workability, and the ideal range of nitrogen for increasing the strength is ~. In the examples, steel containing less than 13% nitrogen bismuth (low-off) is described, and there is no so-called soft and high tensile fracture extension property. In consideration of the fact, the cold workability of the wire is actually poor. Patent Document I2 describes a high-strength two-phase which is excellent in the fineness of nitrogen which is fine and contains 5% or more of nitrogen. However, in the examples, it is noted that the steel containing more than 13% of the nitrogen strontium having an increased strength is not considered to have a high tensile tensile elongation characteristic. &gt; Patent Document 13 describes a two-phase non-recording steel which is low in Ni and contains (10)5% or more of nitrogen and has excellent ductility and deep extensibility. However, in the examples, the fifth series describes a steel which has a strength-enhancing nitrogen content of 0.08% or more in order to improve the deep drawing property of the steel sheet, and has no so-called enamel and high tensile fracture elongation characteristics. Actually, the wire is cold worked. Poor sex. As described above, in the stainless steel, there has been no disclosure of softness and high elongation at break which are required for the cold workability of the wire rod, and it is low in cost and exhibits high corrosion resistance and magnetization. [Patent Document 1] Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. [Patent Document 4] International Patent Publication No. 2 445 〇〇 〇〇 〇 〇 〇 〇 〇 〇 〇 〇 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 327 [Patent Document 8] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. Problem to be Solved by the Invention 5 ❹ 10 15 φ The object of the present invention is to provide a low-cost, high-strength, high-corrosion-resistant screw for Worthing Iron, fat and iron double-phase steel wire, steel wire and screw and its manufacturing method' and cold forging and screw products by controlling the structure, composition and material of low-cost and high corrosion-resistant duplex stainless steel wire High strength. The object of the present invention is to provide a duplex stainless steel wire which is excellent in cold workability and corrosion resistance and which is magnetically affordable, and can greatly reduce the manufacturing cost of a cold-processed product of a conventional Wolster iron non-recorded steel wire and gives Magnetization. Means for Solving the Problem In order to solve the above problems, the inventors of the present invention found that the high-priced Ni content was reduced by the high-corrosion duplex stainless steel and the composition was stabilized (low Depreciation), the volume fraction of the ferrite grain iron phase is controlled to be high, and the tensile strength of the wire and the steel wire is optimized by heat treatment and drawing processing, and the cold forgeability and the screw can be obtained at a low price. The high strength of the product coexists. Furthermore, the inventors of the present invention found that based on the high-corrosion-resistant pure duplex stainless steel having a magnetic ferrite phase and a Worthite iron phase, the high price is reduced and the structure is controlled by composition adjustment (M value control). The work hardening is suppressed by low (c+n), whereby the cold workability which is remarkably improved can be imparted by the low-cost and high-resistance duplex stainless steel wire. The present invention has been completed based on the above findings, and the gist thereof is as follows. 20 200927956 That is, the first aspect of the present invention is a Worstian iron, fat iron double-phase steel wire, which is contained in mass %: C: 0.005%~0.05%;

Si : 0.1 % to 1.0% ; 5 Μ η : 0.1% to 10.0% ;

Ni ··1.0%~6.0% ;

Cr : 19.0%~30.0% ;

Cu : 0.05% to 3.0% ; and N : 0.005% to 0.20% ;

10 and the residue is composed of Fe and substantially unavoidable impurities, and C+N is 0.20% or less, the value of (a) is 60 or less, and the value of (b) is 45 to 85, and stretching is performed. The strength is 550N/mm2~750N/mm2; M=551 - 462(C+N) - 9.2Si - 8.1 Μη -29(Ni+Cu)-13.7Cr—18·5Μο ...(a) 15 F=5.6Cr- 7.1Ni+2.4Mo+15Si-3.1Mn-300C ~ 134N-26.6 (b). In the second aspect of the present invention, it is also possible to add Mo: 1.0% or less in mass% in the first aspect. In the third aspect of the present invention, it is also possible to add B: 0.01% or less in mass% 20 in the first aspect. In the fourth aspect of the present invention, the first aspect may be one or more of A1: 0.1% or less, Mg: 0.01% or less, and Ca: 0.01% or less in mass%. According to a fifth aspect of the present invention, in the first aspect, Nb: 1.0% or less, Ti: 0.5% or less, V: ΐ·0% or less, and Zr: 1.0% or less are added in the mass % 200927956. More than one. A sixth aspect of the present invention is a Worstian iron, fat iron-based duplex steel wire, which is composed of any one of the first to fifth aspects described above, and has a tensile strength of 700 N/mm 2 . ~1000N/mm2. - The seventh aspect of the present invention is a high-strength, high-corrosion-resistant screw, which is composed of any of the first to fifth aspects described above, and has a tensile strength of 700 N/mm 2 to 1200 N/mm 2 . . The eighth aspect of the present invention is a method for producing a high-strength, high-resistance-resistant screw, which is composed of any of the first to fifth aspects described above, and has a tensile strength of 700 N/ MW2~1000N/mm2 of Worstian iron and fat iron-based duplex steel wire, after aging of cold screw, 3 〇〇 ° C ~ 60 (Tc is performed for 1 minute to 100 minutes aging heat treatment. The invention The nine-state sample is a kind of soft two-phase non-conducting steel * 15 wire with magnetization, which is contained in mass %: AC : 0.005%~0.05% ;

Si : 0.1 % to 1.0% ; Μ η : 0_1% to 10.0% ;

Ni : 1.6% ~ 6.0% ; 20 Cr : 19.0% ~ 30.0% ;

Cu: 0.05% to 3.0%; and N: 0.005% or more and less than 0.06%; and the residue is composed of Fe and substantially unavoidable impurities, and C+N is 0.09% or less, and the value of (a) is 60 or less, tensile strength is 700N/mm2 9 200927956 or less, and tensile fracture elongation is 7〇% or more; M=551 - 462(C+N)- 9.2Si- 8.1Mn~ 29(Ni+Cu) -13.7 Cr-18.5Mo (4). In the tenth aspect of the present invention, it is also possible to add Mo: 3.0% or less in mass% 5 in the ninth aspect. According to an eleventh aspect of the present invention, it is also possible to add B: 0.01% or less in mass % in the ninth aspect. According to a twelfth aspect of the present invention, at least one of A1: 0.1% or less, Mg: 〇.01% or less, and Ca: 0.01% or less may be added to the ninth aspect. According to a thirteenth aspect of the present invention, in the ninth aspect, one or more of Nb: 1.0% or less, Ti: 0.5% or less, V: 1.0% or less, and Zr: 1.0% or less are added in mass%. . EFFICIENCY OF THE INVENTION 15 The duplex stainless steel wire for high-strength, high-corrosion-resistant screws excellent in cold forgeability of the present invention does not contain high-priced Ni but ensures excellent cold forgeability, and can be given high corrosion resistance equivalent to SUS304 or higher. Sex and high strength, and can provide high-strength, high-corrosion-resistant screws at low cost. The soft duplex stainless steel wire which is excellent in cold workability of the present invention, 20 which does not contain high-priced, can give remarkably excellent cold workability and magnetizability, and is equivalent to SUS304, SUS316, etc. The anti-corrosion property is excellent, so it can provide excellent effects of high-corrosion products with high quality at low prices. Brief description of the diagram 10 200927956 The diagram shows the relationship between the value of 1 and the volume fraction of the ferrite phase of the wire product. Fig. 2 is a graph showing the relationship between the processing ratio (%) of the steel wire (15% drawn wire) corresponding to the F value and the compressive deformation stress (NW). 5 [Implementation of a cold type] The best mode for carrying out the invention 'Describes the reasons for limitation of the first to eighth aspects of the invention. © To ensure the strength of the screw product, it contains C 0.005% or more. However, if it contains more than 0·〇5%, Cr carbonitride will be formed, and not only corrosion resistance will be deteriorated, but cold forgeability also deteriorates, so it is limited to 0.05% or less. It should be below 0.03%. In order to ensure the strength of the screw product by solid solution hardening and age hardening, N 0.005 ° / is contained. the above. However, if it is more than 0.20%, the cold forgeability will be remarkably deteriorated. Therefore, the upper limit is made 0.20%. A preferred range is less than 150.05%. ❾ For the reason of the above-mentioned cold forgeability, C+N is limited to 0.20% or less. It should be 0.10% or less. In order to deoxidize, Si is contained in an amount of 0.1% or more. However, if it contains more than 1.0%, cold forgeability will deteriorate. Therefore, the upper limit is 1.0%. The preferred range is 0.2% 20 to 0.6%. For the dislocation and the adjustment to obtain a stable Wolsterite structure, it contains 0.1% or more of Μη. However, when the content exceeds 10.0%, the rust resistance and the ferrite iron volume fraction are decreased and the tensile strength is increased, and the cold forgeability is deteriorated. Therefore, the upper limit is limited to i〇.〇%. A preferred range is from 0.5% to 5.0%. 11 200927956 In order to stabilize the Worth Iron Group and ensure cold forgeability, it contains Ni 1.0% or more. However, the longitudinal direction contains more than 6 〇%, and the effect is saturated. On the contrary, the volume fraction of the ferrite-grained iron phase becomes 45% or less, and not only the cold forgeability (tool life) deteriorates, but also the economy is poor due to high price and high price. . Therefore, the upper limit is limited to 6_〇%. A preferred range is more than 3.0% and 5.0% or less. In order to ensure the corrosion resistance and increase the volume fraction of the ferrite grain iron phase, the Worthfield iron is further stabilized and the cold forgeability is ensured, and the buckle is more than 19%. However, the longitudinal or containing effect is also saturated, and conversely the volume fraction of the ferrite phase will exceed 85%, so the strength of the screw product is reduced by 10%. Therefore, the upper limit is limited to 30.0%. The preferred range is 22 〇%~26 〇%.

Cu is used to stabilize the Worthite iron structure, inhibit work hardening, and improve cold forging, and when aging treatment after cold forging, promote age hardening of the ferrite grain iron phase and increase the strength of the screw product. effective. Therefore, it contains 0·〇5/° or more. However, when the content exceeds 3.0 ° / ❶, the solid solution limit of Cu is exceeded and the thermal manufacturability of the material is remarkably deteriorated, so the upper limit is made 3.0%. The preferred range is 0.2% or more and less than ι.〇〇/ο. The VI value of the following formula (a) is helpful for the stability of the iron phase of the Vostian. It is recorded in Iron and Steel, 63 (1977), 772 pages. Once the M value is increased, the system will produce a hard The processing induces the iron phase of the Ma Tian. The cold forging field of duplex stainless steel is 2, and the right M value is over 60. When cold forging, hard processing will be induced to induce the iron phase of the field, and the cold forgeability will be significantly deteriorated (the tool life is inferior and cold forging is broken). Therefore, the Μ value is limited to 60 or less. The preferred range is 4 inches or less. Μ'551 - 462(C+N) - 9.2Si - 8. ΙΜη - 29(Ni+Cu) ...(a) ~13·7(:γ-18·5Μο 200927956 5 Ο 10 15 ❹ 20 The following (b The F value of the formula is helpful for the volume fraction of the ferrite grain phase. It is recorded as an indicator of the fairness of the patent publication No. 7-74416. Once the F value is increased, the ferrite phase will increase. The figure is used to investigate the volume fraction of the F-value and the ferrite-grain phase of the duplex stainless steel wire products. If the F value is 45 or more, the volume fraction of the ferrite-grained iron phase becomes 45 vol.% or more, indicating high endurance and low processing. The hardening property (Fig. 2) allows the strength of the product (tensile strength of the screw shaft portion) to be increased to 700 N/mm2 to 1200 N/mm2, and the cold forgeability of the head can be ensured. Therefore, the F value is limited. 45 or more. As shown by the relationship between the processing ratio (%) and the compressive deformation stress (N/mm2) corresponding to the F value in Fig. 2, when the F value is less than 45, the work hardening becomes large, and the cold forgeability (forging fracture, Tool damage) increases and deteriorates. On the other hand, if the F value exceeds 85, the soft ferrite phase will exceed 85%, and the strength of the Wostian iron phase will decrease, so the strength of the screw product is reversed. Lower, so the upper limit is 85. The preferred range is 50~80. F=5.6Cr-7.1Ni+2.4Mo+15Si-3.1Mn-300C-134N—26·6 (b) Stretching of wire The strength is greatly advantageous for the cold forging system. When the tensile strength of the wire is less than 550 N/mm 2 , the strength of the cold forged part such as a screw is low, and the value as a high strength product is low. Therefore, the lower limit is limited to 550 N/mm 2 . On the other hand, when the tensile strength of the wire exceeds 750 N/mm 2 , the cold forgeability is remarkably deteriorated (the tool life is deteriorated, and the cold forging is broken). Therefore, the upper limit is 750 N/mm 2 . The preferred range is 600 N/mm 2 to 700 N. /mm2.

Mo is an effective element for improving the resistance to rot, adding 0.1°/. The above can be stably obtained. However, when the content exceeds 1.0%, not only the cost of the material increases, but also the material hardens and the cold forgeability deteriorates. Therefore, the upper limit is limited to 1.〇〇/. . 13 200927956 The preferred range is 〇·2°/〇 or more and less than 〇.5%. The lanthanide system is effective in improving the hot workability, and the addition of 〇 〇〇 1% or more can stably obtain the effect. However, boride is also produced when the content exceeds 〇.〇1%, and the corrosion resistance and cold forgeability are deteriorated. Therefore, the upper limit is limited to 〇 〇 1%. Preferably, the range is from 0.002% to 0.006%.

Since Al, Mg, and Ca are effective for the deoxidation system, it is possible to stably obtain the effect by adding A:: 0.005% or more, Mg: 0.001% or more, and Ca: 0.001% or more. However, each contains more than A1: 〇 ι〇/. ,

When Mg: 0.01% and Ca: 0.01%, the effect is also saturated, and conversely, © 1 〇 produces a rough oxide (intermediate), and cold forge fracture occurs. Therefore, the upper limits are A1: 0.1%, Mg. 0.01%, and Ca: 0.01%. A preferred range is A1: 0.1% to 0.06%, Mg: 0.002% to 〇.〇〇5%, and Ca: 0.002% to 0.005. /. More than one type.

Nb, Ti, V, and Zr are effective for suppressing the formation of Cr carbonitride and ensuring corrosion resistance. By adding Nb: 0.05% or more, Ti: 0.02% or more, 'V: 0.05%, Zr: 0.05 More than one of the above types can be stably obtained. However, it contains more than Nb : 1.0% ' Ti : 0.5%, V : 1.0%,

When Zr: 1.0%, the effect is also saturated' and conversely, coarse precipitates are produced, and cold forge fracture occurs. Therefore, the upper limit of each element is specified. Preferably, the range of 20 is one or more of Nb: 0.1% to 〇.6%, Ti: 0.05% to 0.5%, V: 0.1% to 0.6%, and Zr: 0.1% to 〇.6%. Usually, as an unavoidable impurity, the steel contains oxygen in the process, and in the aspect of the invention, it is preferably 0. 01% or less as an unavoidable impurity. 14 200927956 5 ❹ 10 15 20 The wire is drawn into a drawn steel wire, and the tensile strength of the steel wire is helpful for the cold forging and the strength of the screw product. When the tensile strength of the steel wire is less than 700N/ At mm2, the strength of the screw product becomes low, and the value as a high-strength product is lowered. Therefore, the lower limit is limited to 7 〇〇N/mm2. On the other hand, if the tensile strength of the steel wire exceeds 1000 N/mm2, the cold forgeability will be remarkably deteriorated (tool life is deteriorated, and cold forging fracture occurs). Therefore, the upper limit is 1000 N/mm2. A preferred range is 750 N/mm 2 to 900 N/mm 2 . The tensile strength of the high-strength screw of the present invention is increased in strength during the aging heat treatment after the wire drawing and cold forging. At this time, if the tensile strength of the screw product is less than 700 N/mm2, the value as a high-strength screw product is low. On the other hand, if the tensile strength of the screw product is 12 〇〇N/mm 2 or more, the cold forging cost is remarkably deteriorated due to cold forging cracking or tool damage or the like. Therefore, the upper limit of the tensile strength of the 々 screw system is 12〇〇N/mm2. The preferred range in which the economic effect can be exerted is 8 〇〇 N/mm 2 to 1000 N/mm 2 . After the steel wire of the present invention is formed into a screw by cold forging, in order to effectively increase the tensile strength of the screw product, it is effective to perform 30 (rc or more, heat aging treatment for one minute or longer). If it exceeds 6 deaths, it will age and the tensile strength of the screw products will decrease. Therefore, the upper limit is 6 〇〇 (&gt;c. The preferred temperature range is 4GGt~55G °C. Also, when holding (4) more than 1〇 In the minute, not only the effect of age hardening is saturated, but also the tensile strength of the screw product is lowered due to overaging. Therefore, the upper limit of the holding time is 100 minutes. The preferred holding time range is 5 minutes to 6 inches. Minutes. Reasons for limitation of the ninth to thirteenth aspects of the present invention. To ensure the strength of steel, the C system is added with 0_005% or more. However, when added over 15 200927956 0.05%, not only cold workability is deteriorated, but also &amp; Carbide and corrosion resistance are also deteriorated. Therefore, the upper limit is made 0.05% or less. The preferred range is 〇〇1% to 0.03%. To ensure the strength of cold-worked parts by solid solution hardening, N-type addition of 5 0.005% or more .but' If it exceeds 〇.〇6% or more, the tensile strength will increase and the cold workability will deteriorate. Therefore, the upper limit is less than (four) 6%. The general-purpose two-phase steel is used to reduce the use of high-priced alloying elements, and G Q6% is added. The above N, only the aspect of the steel, the control of the organization and the composition of the balance, and I will suppress the N content to a low level, soft and make the cold workability of the wire material greatly increase the 〇10 characteristics. The preferred range is 0.02% or more and less than 〇〇5%. For the reason of the cold workability, C+N is limited to 〇〇9% or less, preferably 0.07% or less. Adding (10) oxygen 'Si_ plus 〇·1% or more However, if it is added more than i, it will be hardened and the cold workability will be deteriorated. Therefore, the upper limit is ι〇%. Preferably, the range of 15 is 0.2% to 0.6%. For deoxidation and as a fertilizer to obtain iron The two-phase organization of the Shi Tiantie's re-construction of the stability of the Worthite iron structure, the addition of Mn to the Mn system is 1% to e. When the addition exceeds 1G.〇%, the corrosion resistance and strength increase, cold processing The property will deteriorate. Therefore, the upper limit is limited to 100% or more. The preferred range is 0.5% to 5.0%. Low devaluation and the acquisition of the dual phase of the ferrite iron + Worthite iron, and further stabilize the Worthite iron organization and ensure the cold workability, add the coffee. However, even if added more than 6.0%, not only the effect is Yarn, and the price of Ni is so high that the economy is inferior. Therefore, the upper limit is limited to 6.〇%. The preferred range of 200927956 is 2.0%~5.〇〇/.. To ensure corrosion resistance (4) Read the fat iron + The two-phase organization of Worthite Iron's further stabilizes the Worthite Iron Group and ensures cold workability. The addition of 1% is more than that. However, even if it is added more than %, the effect is not only saturated, but also cold. X sex is deteriorating. Therefore, the upper limit is limited to 3〇 〇%. A preferred range is 20.0% to 26.0%. In order to reduce the enthalpy and obtain the double-phase structure of the ferrite iron + Worthite iron, the Worthite iron structure is stabilized, the hardening of the hardening is suppressed, and the cold workability is improved. The system contains CU 0.05% or more. However, if it is more than 3% by weight, the solid solution limit of H) Cu is exceeded and the thermal manufacturability of the material is remarkably deteriorated, so the upper limit is made 3.0%. The preferred range is less than 丨.〇%. The enthalpy of the following formula (a) is helpful for the stability of the iron phase of Vostian. It is recorded in Iron and Steel, 63 (1977), 772 pages. Once the devaluation is increased, it will produce a hard Processing induced the iron phase of the field. The cold forging field of the two-phase non-recording steel 15 is combined. If the enthalpy value exceeds 60, the hard processing will produce a hard process to induce the iron phase of the granule, and the cold workability will be significantly deteriorated. Therefore, the river value is limited to 60 or less. A preferred range is 40 or less. M=551-462(C+N)-9.2Si-8.1Mn-29(Ni+Cu) -13.7Cr-18.5Mo (4) The tensile strength of the 2〇 wire rod is very helpful for the cold workability of the wire. If the tensile strength of the wire exceeds 700 N/mm 2 , the cold workability is remarkably deteriorated. Therefore, the upper limit is limited to 700 N/mm2. On the other hand, when the tensile strength of the wire is less than 500 N/mm2, the strength of the cold-worked product is too low, and the value as a product is lowered. Therefore, the lower limit should be 500N/mm2. The preferred range is 17 200927956 500N/mm2 to 650N/mm2. The tensile fracture extension of the wire rod is greatly advantageous for the cold workability of the wire. When the tensile fracture elongation of the wire is less than 7〇%, the cold workability such as cold drawing processing and cold forging property is deteriorated. Therefore, it is limited to 7〇% or more. Preferably, the range of 5 is 75% or more. The magnetization is a function that is not required for the Worthfield iron-based stainless steel, and the magnetization is industrially characterized by the following functions, that is, the workability of the magnetic tool can be improved by the magnetization of the magnetic tool when the fastener is locked. When a wire mesh or a screen (especially a conveyor belt for foods) is mixed with the food 10 due to the falling off of the material, a magnetic sensor can be used to prevent mixing. Therefore, the present invention limits the magnetizability. Preferably, the relative magnetic permeability is 3.0 or more.

Mo is an element effective in improving corrosion resistance, and can be stably obtained by adding 〇1% or more. However, if you add more than 3. /. Not only the material hardens, but also the σ phase precipitates and the cold workability deteriorates remarkably. Therefore, the upper limit is limited to. 15 The preferred range is 0.3% to 1.0%. The lanthanum extract is an effective element for hot workability, and it can be stably obtained by adding 〇 〇〇 1% or more. However, boration occurs when added more than 〇.〇1%

A preferred range is from 0.002% to 0.006%.

When Mg: 0.01% and Ca: 0.01%, the effect is also saturated, and the rough oxide (mediation) is deteriorated in cold workability. It must be packaged and, on the contrary, produced. Therefore, the upper limit is 18 200927956 as A1 . 0.1%, Mg : 〇.〇1〇/0, Ca: 0.01%. A preferred range is A1: 0.008%~〇.06%, Mg: 0.001%~〇·〇〇5%, Ca: 〇 〇〇1〇/. ~0·005% of one type or more. 5 ❹ 10 15 Ο

Nb, Ti, V, and Zr are effective for suppressing the formation of Cr carbonitride and ensuring corrosion resistance. By adding Nb: 0.01% or more, Ti: 〇·〇ι% or more V: 0.01% or more, Zr: More than one of 0.01% or more, the effect can be stably obtained. However, when the content exceeds Nb: 1.0%, Ti: 0.5%, V: 1 〇%, and Zr: 1.0%, the effect is also saturated, and conversely, coarse precipitates are generated, and cold workability is deteriorated. Therefore, the upper limit of each element is specified. A preferred range is one or more of Nb: 0.05% to 〇.6%, Ti: 0.05% to 0.5%, V: 〇.1 〇 / 0 to 0 6%, and Zr: 0.05% to 0.6%. Usually, as an unavoidable and avoidable impurity, the steel contains oxygen in the process, and in the aspect of the invention, as an unavoidable impurity, it is preferably 1% or less of oxygen. [Embodiment 1] Hereinafter, Embodiment 1 of the present invention will be described. The chemical compositions of the steel of Example 1 are shown in Tables 1 to 4. 19 200927956 Chemical composition (mass%) S 卜o On S or〇^Ti inch CN Ό Os o 〇〇 VO ro jrj CN VO 0 1 ϊ&gt; p 卜 a; cn 〇 〇 &lt;N ri ^Ti r- V〇〇r4 o 卜o inch r〇rji Os vd ^T) 00 ΓΟ 00 'O inch 〇〇 · m C+N 〇rH 卜o S d 〇oogo S d 〇soosd S o me 1 1 1 1 1 1 1 1 1 1 1 1 1 1 〇gdv〇doos 〇osdgo 〇〇〇sodso 〇〇0.006 0.006 0.006 0.005 0.005 0.005 0.005 0.005 0.006 0.005 0.005 0.005 0.005 0.006 1 i 1 1 1 1 1 1 1 1 1 1 1 i U inch O' ^T) d inch 〇o rn cn O inch d 00 o 00 o inch 〇d in 〇〇ooo 〇〇oo 〇o O oodoodoooo 〇oo c5 oo »r&gt; CN a ra 00 a CN inch cn &lt;N艺CN VO CN inch»r! ΓΊ CN Six VO uS CN cs Ch CN iH Art inch &lt;N inch · inch in in 00 00 On 卜 iri rn m X/l 0.001 0.001 0.001 0.001 0.002 0.001 0.001 0.003 I 0.003 0.001 0.003 0.002 0.006 0.003 0.024 0.038 0.024 0.022 0.026 0.025 0.024 0.021 0.032 0.023 0.026 0.027 0.033 0.033 1 cn CN lH r-^ CN 〇 〇 00 On σ&gt; Os μ VO o \〇o in o CN 〇00 ov〇〇卜 od 〇\ 〇mom O tn o in O ug O odr*H odoosogosdsooos 〇soso T—^ oooo soil W scale c 03 UQ m pi OK 1—&lt; s % 4念紫綦20 200927956

Μ ϊ&gt; 00 d 〇\ o »n inch a\ r&gt; 00 VO ri ID cs o ON 00 On in δ in On S domain v〇(N r*H in iH in -30.2 O) tTi in ο rr «H sd 1 CN CM 1 *ni〇rH TH On m \D ΓΟ ? S g CN tH 卜 o rH to 1-H CN g 容 g in SU oddo ο oddooodddo c&gt; 〇smooosod 击 4nl, 1 1 1 ι/ Od od 1 oo 〇d 〇o inch omdo inch d &gt; 1-Ή rn 〇〇ffl g1 o CN o Ψ{\ CQ subject to cS u 5 Ϊ P &gt; o CQ a U &gt; Ϊ igg iH s 1-H m TH T—HS ssosssoo 〇ο ooooodoooooog? Ο o ir&gt; oo in or〇Ο o _〇omoooomoso 0.004 cn O 3 oododdddddddddodo B 1 1 1 1 j 0.035 1 1 so 1 1 1 1 1 sosogo' so inch d mouth u CN inchooo r- o VD 〇iT) ov〇o 卜d inch oo in od inch omooo ο soo rn 〇\ d TH TH rH lH 1-H lH iH CN CN &lt;N 00 ΙΛ&gt; yn in CN in Cs m 00 ro cs iH CN oq CO CN CN CN vS CN US CN cn (N CN CN cn cs j^H inch cn inch m inch inch inch inch inch inch inch inch Tt·iH r*H m 1-H inch inch · ch cn cs xn 00 O 〇so τ~Η ο Ο so SOS 〇_〇m O so ΓΟ 〇r〇〇&lt;N 〇m O soi-H oo 〇o ο ο oo c&gt; ooo 〇c&gt; 〇c5 oo PW CN s CN s CN s S 00 g VO so 卜 so CN g un sm S c〇gos 00 sssodo ο Ο odooooddoooo 1 〇 00 CN CN m cs C\ (N CN CN CN &lt;N 00 00 O) oo 卜 m inch od inch o ιτ&gt; ο iT) d VO o inch 〇m O inch dmo inch dv〇ov〇〇 inch o ro d inch o rn (J os § S gosg ^-H oss S gssosood ο oooooooodoooo pq u Q o Ph cx Ρί c /) &gt; XN ffl PQ uu QQ ω ω 4诤 綦 21 200927956 Chemical composition (mass%) in CN (Ν Ν 00 Os &lt;Ν 〇〇ON cn 00 〇 〇 \ &lt;N 卜 c&gt; m inch oo Oo Os On 00 ^j· 00 vd ι&gt; ^Τ) inch · Ον 'Ο r—^ o 122.2 m oi rp CN 1 00 VO oo o 1 CN Equation 1 C+N 〇\ o Art ο ο 卜 dso CO 1-H d 〇o TH doso Others 1 1 1 1 1 1 1 1 1 1 1 Csl T—H o ο 艺ο 艺ο cn T&quot;H oso rH iH dg CD goooo 〇0.005 0.005 0.005 0.004 0.004 0.004 0.006 0.006 0.005 0.005 0.005 1 1 1 1 1 1 1 1 1 1 1 1 rn Ο Ο ο 〇〇 ) ) ) Ο oo oo oo oo oo oooo 〇〇oooooooo CN CN mm· CN &lt; Ys (Ν Ν Ν Ν Ν Ν Ν Ν Ν Ν Ν Ν Ν Ν Ν Ν Ν Ν Ν cr cr cr cr SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI / / / / / / / / / / 0.002 0.003 0.003 0.002 Oh 0.025 0.026 0.018 0.033 0.022 0.022 0.024 0.025 0.032 0.023 0.025 1 CN — (Ν in fH 卜 00 inch · inch · inch · in rt- OO cn m 〇m ο 21 Ο 卜 d l&gt; c5 o inch d ^T) o VO ouo S ο S ο sdosdsdsosogooo CQ &lt; Q &lt;&lt; [Xi &lt; O &lt; 5 &lt; • 4诤浮綦% Η 瑞伞 4 33 璲※ 22 200927956 Chemical composition (mass% rH vd ID 卜(N 〇〇r*H (Ν 窆cs 1-Η rn o per inch VO inch 1 00 CN ON 'P*&quot;H r f -49.2 inch rn CN οο CN 〇\ 〇 inch od &lt;Ν o (N s ο vd (Ν C+N Ο md cs d inch o 〇ι-Η CS 1-H 〇Η Ο CS dgo (Ν Τ* Η Ο Η 1 B : 0.023 1 Wi 0 d CdC 1 Ca : 0.018 ΓΠ i 00 〇V : 1.8 Zr : 1.5 1 I d »—H c&gt; s 〇CN O g 〇g Ο gd § Ο g 〇 og Ο 〇0.005 0.006 0.005 0.006 0.007 0.005 0.004 0.005 0.006 0.005 l ____ 0.005 1 1 CN CN d 1 1 1 1 1 1 1 1 Divination d r- O VO 〇 inch 〇 in vn d ο md (N d inch Ο 〇S 3 Oood 〇〇〇〇ο ο ο ο ο ο oood Ο Ο ΰ ON ri &lt;N in m inch m cn m 弍m inch CN (N i〇οο |^Η O) — inch · οο inch · 〇\ inch · Bu rn a τ/ι 0.001 0.002 0.004 0.003 0.002 0.002 0.003 0.002 0.003 0.002 0.003 Oh 0.026 0.025 0.032 0.028 s Ο 0.031 0.032 0.027 0.027 0.026 0.026 2 σ\ rn iH cs ί~Η ο cn inch (N m CO ΟΝ this od In d 卜d ο 卜d 卜dv〇d inch Ο \〇Ο usdsdsogo S ο s ο s ο g d&gt; so S Ο customer 1 5 〇&lt; Ph &lt; σ 00 &lt; 5 1 4 4 •33 ※ 23 200927956 The steels of these chemical compositions are dissolved in a 3〇〇kg vacuum melting furnace and cast into a cast piece of 0 180mm, which is required to be 5.5mm~0 6 5_ The secret material rolling was carried out, and the hot rolling was completed in a 1 G pit, followed by a continuous heat treatment at 105 (TC was kept for five minutes and subjected to water-cooling dissolution treatment, after which it was pickled and made into a wire product. Thereafter, the grass_film treatment was carried out, and the cold-drawn light wire was added with W05.2 mm to prepare a cold steel wire. After that, the hexagonal screws were subjected to about root cutting by cold forging and rolling. And part of it is 3 〇 (rc~65〇, i L, hold for 3 minutes)

~200 minutes of aging treatment. After that, the hexagonal screw product was made of all the screws by barrel polishing. The evaluation was carried out on the tensile strength of the steel wire, the fraction of the iron phase of the steel wire, and the cold forgeability (with or without cracking, with or without tool damage)' tensile strength and corrosion resistance of the screw product. The evaluation results are shown in Table 5 to Table 8.

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VO &gt;r5 σ v〇% wi % Ό 6·inch It 6·inch cs 9ΌΙ 90l 901 ο § 0 卜 9 0 9 9 089 089 9 9 louss.s ς.ς MV AV nv Hv sv 19 09 6S oos ΙΛ 1Η»)Φ %S墀浮#4-33 Bullying area ※ 28 200927956 The mechanical properties are evaluated by tensile strength and fracture extension in the tensile test of JIS Z 2241. The steel wire system of the present invention is all in the range of 65 〇N/mm2 to 1000 N/mm2, and the screw products of the examples of the present invention are all in the range of 7 〇〇 N/mm 2 to 1200 N/mm 2 and are excellent in high strength. 5 10 15 20 The volume fraction of the ferrite phase of the steel wire is the longitudinal section of the mirror-polished steel wire. The ferrite phase is colored by the Murakami reagent, and the volume fraction is obtained by image analysis to calculate the volume fraction. The iron fraction of the steel wire system of the present invention is in the range of 45 vol.% to 85 vol.%. Cold forging is performed by a three-stage upsetting machine for 5 〇〇〇 forging of the hex head and evaluated for the presence or absence of forging rupture and tool damage. The tool life is evaluated as Q when no tool damage occurs, and the tool life is evaluated as X when the guard damage occurs. There is no cold cracking in this hair _, the tool life is 〇, and the cold forging property is excellent. The corrosion resistance of the screw product was tested by the salt spray test of JIS z 2371, and the spray test was performed for every ten screws of each screw product, and evaluated by the clock. In the case of rust and only a small degree of rust, the evaluation of septic is Ο, and there is an overflow 趟, the whole surface _, and the durability evaluation Μ. The screw products of this hair _ all of the impurities are Ο. On the other hand, in Comparative Example No. 38 and Ν〇·6ΐ, in addition to the scope of the present invention, the cold forgeability, the strength of the screw product, and the resistance to corrosion are inferior, and the advantages of the present invention are clearly apparent. [Embodiment 2] Hereinafter, Embodiment 2 of the present invention will be described. 29 200927956 The chemical composition (% by mass) of the steel (test material) used in Example 2 is shown in Tables 9 and 10.

30 200927956

(N赛m CN cs 00 «〇in inch rn 00 〇\ cn oo 衮pm 00 CNj oo w-» vd cn 卜r&quot;H VO 耷CN inch CN Γ〇T*H OO cn IS dgosdsosddsdsososooso sosdsosososososo SOS osog O 1 1 1 1 1 1 1 1 I i 1 oo 1 :0.003 soosoo inch · rn v〇o inch o iH o 'S soo 0.002 go CQ ¢3 c3 i P &gt; Λ 0 1 CQ c3 i iH odsosososososo SO psososo F&quot; H o SO soso C4 oososoddso 〇sd 〇0.006 0.006 丨0.005 0.005 0.006 0.005 0.005 0.006 0.007 0.005 0.005 0.005 0.003 0.005 0.005 0.005 0.005 0.005 0.005 0.006 0.006 0.005 0.006 0.005 0.007 1 [1 ll 1 1 i ! 1 1 i 0.035 1 1 so 1 1 1 1 1 1 so 1 〇1 1 1 I 1 1 1 1 i oo &lt;N 1 1 1 1 1 1 1 1 1 1 CS o C&lt;1 o 5 o S 〇cn inch o CO o &lt;N o &lt;N o 00 o »〇CN* m· cn &lt;N 〇&lt;N cn 〇ooo CN rH o (S o cn o CS o 〇CM 〇ΰ *ri CN Os Csi CN in cn CN o 戈寸cn CN On 00 uK &lt;N &lt;N CN &lt;ri CN 卜r4 (N in c4 CN &lt;N rn &lt;N m ri CN CN &lt;N (N On &lt;N CN CN CN 00 &lt;N CS ΓΛ CS 00 &lt;N CS -CNJ g uS cn inch · Os oo i〇cs to &gt;/S r&lt;*i ΓΠ CO rn OO Rn 〇i〇»ri 〇H in cs in &lt;S m in &lt;S &lt;S &lt; & m τί1 ϋ〇0.001 0.002 0.001 0.001 0.003 0.001 0.002 0.001 0.002 0.001 0.002 0.001 0.001 0.002 0.002 0.002 0.002 0.003 0.003 0.003 0.003 0.004 0.005 0.004 Ah ! 0.025 0.016 ! 0.025 0.024 0.032 0.018 0.019 0.025 I 0.028 | 0.032 | 0.022 | 0.027 | 0.028 0.026 I 0.026 1 0.027 1 0.026 0.032 i 0.025 | 0.023 ,0.023 0,031 0.025 "0.028 1 1 o &lt;N CN o &lt;N卜σί yn *ri &lt;N_ 〇\ rn V) ΓΠ CN cn CN cs fN cs (N o CN cs fS cs 00 ON oo 00 &lt;n 〇\D 〇0\ dv〇o 00 o inch 〇«Ο 〇 Inch oo om 〇o \〇o inch d IT) d inch dmd inch od \D 〇 inch o CO inch oooo S oso S opso S osopsosososo 1—&lt; osdsdod S oso S ososososo lt.L3 4«β &lt; m Ffl PQ U CQ PW PQ tLl ϋ PQ s CQ a ffl h-1 PQ s CQ 1 O PQ Pu PQ 〇m PQ pH & GGG 4畲S綦31 200927956 0Ι&lt; Μ 24.7 1 CN -42.6 00 -27.3 62.0 -59.2 -54.6 -33.9 VO 41.0 VO m 23.2 26.2 CO CN mm 70.3 -47.4 C+N 0.08 0.09 51 0.06 0.05 0.06 0.04 0.04 0.04 0.03 0.06 0.04 0.04 0.03 0.05 0.04 0.04 0.03 0.05 0.03 dl 0.09 Others 1 1 1 1 1 1 1 ! 1 1 m &lt;N 〇d CQ 1 Me : 0.015 Ca : 0.018 Nb : 1.3 00 d 00 &gt; Zr : 1.5 1 1 1 0.02 0.07 0.05 0.03 0.02 0.03 0.02 0.02 0.02 0.02 0.03 0.02 0.02 0.02 0.03 0.02 0.02 0.02 0.02 0.02 0.05 0.05 Ο 0.006 0.005 0.005 0.005 0.007 0.006 0.005 0.005 0.005 0.005 0.005 0.006 0.004 0.005 0.005 0.005 0.005 0.004 0.005 0.005 0.005 0.005 0.006 0.006 0.005 0.006 0.006 1 1 1 1 1 ti 1 1 1 1 i 0.15 1 i 1 1 1 1 i 1 1 Ο S 1 1 1 1 1 I 1 i 1 ! H 1 i 1 i 1 1 1 1 ltd υ o CO o &lt;N o CO o CN o CN Ooo (N o Ί ml 0.05 o &lt; N dmomodmo fS o 1-H ooodm CN m CN 23.3 23.0 22.8 23.3 23.3 m iH 30.3 F-H m CN 23.2 m 22.8 22.8 cn cn r^i CN 23.2 22.9 22.8 22.7 22.8 OO • One CN wi Ό *rl to m 1 3 inch iri v〇vi in m (N inch ir> tn inch*T) m inch Vi Inch &lt;^l CO 0.004 0.003 0.003 0.002 0.004 0.004 0.003 0.003 0.003 0,002 0.002 0.003 0.003 0.004 0.003 0.002 0.003 0.001 0.002 0.003 0.004 PL, 0.032 0.027 0.028 0.024 0.032 0.028 0.023 0.023 0.023 0.028 0.027 0.032 0.033 0.032 0.03 0.032 0.033 0.028 0.028 0.027 0.028 0.025 S OO CN CN 〇OO 00 Os m CN 00 fn 00 00 &lt;N &lt;N CN (N (N CN (N CN oi 〇\ iH ON o 〇d inch o 3 o VO d OO o 〇〇o Inch doo 卜o \oov〇〇v〇〇»〇d iT) ov〇o inch o 〇 inch C) od U 0.06 0.02 0.05 0.03 0.03 0.03 0.02 0.02 0.02 oo 0.03 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.03 0.01 0.05 0.04 steel Mark ΚΠ PQ gm _ N 0Q muuo 8 S u 8 S t-id δ . ※域* 32 200927956 The steels of these chemical compositions were melt-cast into a 180 mm slab in a 150 kg vacuum melting furnace, and the slab was hot rolled at 05.5 mm and finished at 1050 °C. It is hot rolled and held directly at 1050 ° C for five minutes, and subjected to continuous heat treatment of water cooling, followed by pickling to form a wire. 5 Thereafter, the cold-stretched wire was processed to 02.0 mm by a general process, and the steel wire was bent into a mesh-like wire mesh for a conveyor belt, thereby being subjected to cold working.

The evaluation was performed on the tensile strength, tensile fracture elongation, cold workability, corrosion resistance, and magnetizability of the wire. The evaluation results are shown in Table 10 11 and Table 12.

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Remarks 5 ife i K- Ni raw material costly magnetization - Vf cup and saucer 1 J 腐 〇〇〇〇〇〇 〇〇〇〇〇〇 1 〇〇〇〇〇〇〇〇〇〇〇 cold workability ^ 1 ^ 1 XI ^1 〇 1 Xl •Xl 彳丨Xl 〇1 ! Tensile fracture extension (%) 〇〇JO o 1 SI $1 CM cs rn CN 00 Ης: Take 1 690 710 730 〇〇〇VO 720 660 560 650 680 1 720 620 610 620 610 650 640 650 ο s 720 730 620 Steel mark CZ5 « Η PQ PQ &gt; W BW 1_ X PQ N P3 &lt; u CQ 〇uue ω u Ph U ou ffi u 0 uu CM u 〇v〇00 00 00 ON 〇 〇〇\ m 〇\ 〇\ On 00 ON ON 〇\ o vH o CN 〇CO 〇o iTi O o Distinction % j 3 35 200927956 Tensile strength and tensile fracture extension of wire, stretched by 玎822241 The tensile strength and fracture extension in the experiment were evaluated. In the example of the present invention, the total tensile strength of the wire is 5 〇〇] ^ / 1111112 ~ rupture extension $ · 70%. 5 Cold workability is flattened by cold drawing and subsequent wire mesh processing. The cold formability when the wire is not broken or broken and can be formed into a wire mesh is evaluated as 〇, and it is evaluated as ^ 时 when it cannot be formed into a wire mesh due to breakage or breakage. The wire of the example of the present invention is free from breakage and breakage, and is excellent in cold workability. - Corrosion resistance After grinding the surface of the pickled wire with #500, a 1 hour spray test was carried out according to the salt spray test of JIS Z 2371 to evaluate whether or not there was rust. If there is no rust and only a slight degree of ecchymosis, the corrosion resistance is evaluated as 〇, and when there is an overflow and the entire surface is rusted, the corrosion resistance is evaluated as 乂. The evaluation of the corrosion resistance of the steel of the present invention is all 〇. The magnetization is attached to the wire mesh and the relative magnetic permeability is measured by a ferrite meter (simple magnetic permeability meter). When the relative magnetic permeability is more than 3. 〇, the magnetization is clearly confirmed to have magnetization, and when it is less than 3. 〇, it is evaluated as non-magnetizability. On the other hand, Comparative Examples No. 86 to No. 107 are inferior to the scope of the present invention, and the advantages of the present invention are apparent from the viewpoints of poor cold workability, corrosion resistance, cost, and magnetizability. 20 Industry Applicability According to the above embodiments, the high corrosion-resistant duplex stainless steel wire of the present invention which does not contain high-priced Ni has excellent cold forgeability, and can make the screw product high in strength and low in cost. The high-strength and high-corrosion-resistant screws are provided, and the nuts are also applicable, which is extremely useful in the industry. 36 200927956 5 % As is apparent from the above embodiments, the present invention can produce a soft and magnetizable inexpensive duplex stainless steel wire, which provides remarkably excellent cold workability, and can be given a Worstian iron equivalent to SUS304, SUS316, etc. It is corrosion-resistant to stainless steel, etc., and can provide low-corrosion, high-corrosion-resistant cold-worked products such as screws, pins, wire mesh, metal wires, ropes, springs, etc., which are extremely useful in the industry. A simple description of the C pattern 3 u &gt; Ο &quot; Figure 1 shows the relationship between the F value and the volume fraction of the ferrite phase of the wire product. 10 Fig. 2 is a graph showing the relationship between the machining rate (%) and the compressive deformation stress (N/mm2) of a steel wire (15% drawn wire) corresponding to the F value. [Main component symbol description] (none) 37

Claims (1)

200927956 ., VII. Patent application scope: 1. A high-strength, high-corrosion-resistant high-strength, high-corrosion-resistant screw for Worthite iron and ferrite-grained iron-phase dual-phase steel wire, which is contained in mass%: C: 0.005% ~0.05%; Si: 0_1%~1.0%; Μη: 0.1%~10.0%; ·Ni: 1.0%~6.0%; -Cr: 19.0%~30.0%; ◎ Cu: 0.05%~3.0%; and N: 0.005%~0.20%; and the residue is composed of Fe and substantially unavoidable impurities, and C+N is 0.20% or less, the value of (a) is 60 or less, and the value of (b) is 45~ 85, and tensile strength is 550N/mm2~750N/mm2; M=551 - 462(C+N) - 9.2Si- 8.1 Μη -29(Ni+Cu)_ 13.7Cr- 18·5Μο ... (a F=5.6Cr-7.1Ni+2.4Mo+15Si-3.1Mn-300C q-134N-26.6 (b). 2. For the high-strength, high-corrosion-resistant screws for the high-strength, high-corrosion-resistant screws, the Worthite iron and the ferrite-coated iron-phase dual-phase steel wire, which are excellent in cold forgeability in the first paragraph of the patent application, and contain Mo: 1.0% or less by mass%. 3. As for the high-strength, high-corrosion-resistant screws with high-strength and high-corrosion resistance, the Worthite iron and the ferrite-coated iron-phase duplex steel wire, which are excellent in cold forgeability in the second paragraph of the patent application, are contained in mass % B: 0.01% or less. 4. The high cold forgeability of any of the first to third patent applications. 38 200927956 Worstian iron and ferrite iron double-phase steel wire for strength and high corrosion resistance screws, which are in mass% It contains: A1 : 0.1% or less; Mg · · 0.01% or less; and Ca: 0.01% or less. 5. For the high-strength, high-corrosion-resistant screws with high-strength, high-corrosion-resistant screws, such as the Worthite iron and the ferrite-grained dual-phase steel wire, which are excellent in cold forgeability in the second paragraph of the patent application, which contain the mass %: Nb: 1.0% or less; Ti: 0.5% or less; V: 1.0% or less: and Zr: 1.0% or less. 6. For the high-strength, high-corrosion-resistant high-strength, high-corrosion-resistant high-strength, high-corrosion-resistant high-strength, high-strength, high-strength, high-strength, iron-based, dual-phase steel wire, which contains: Nb: 1.0% or less; Ti: 0.5% or less; V: 1.0% or less: and Zr: 1.0% or less. 7. A Worthite iron and a ferrite-granular dual-phase steel wire for high-strength, high-corrosion-resistant screws excellent in cold forgeability, which has the chemistry described in any one of claims 1 to 6. Composition, and tensile strength is 700 N/mm2 to 1000 N/mm2. 8. A high-strength, high-corrosion-resistant screw having the chemical composition described in any one of claims 39 200927956 1 to 6, and having a tensile strength of 700 N/mm 2 to 1200 N/mm 2 . A method for producing a high-strength, high-corrosion-resistant screw, which has the chemical composition described in any one of claims 1 to 6, and has a tensile strength of 700 N/mm 2 to 1000 N/mm 2 . The Worthfield iron and fat iron-based duplex steel wire are subjected to aging heat treatment at 30 ° C to 600 ° C for 1 minute to 100 minutes after cold screw forming. 1〇_- A soft, duplex stainless steel wire with excellent cold workability, containing % by mass: ® C : 0.005%~0.05% ; Si : 0.1%~1.0% ; Μη : 0.1 %~10.0% Ni: 1.6%~6.0%; Cr: 19.0%~30.0%; Cu: 0.05%~3.0%; and N: 0.005% or more, less than 0.06%; 残 and the residue is composed of Fe and substantially unavoidable impurities And C+N is 0.09% or less, the value of (a) is 60 or less, the tensile strength is 7〇〇N/mm2 or less, and the tensile fracture elongation is 7〇〇/〇 or more; * M=551 - 462(C+N)- 9.2Si- 8.1Mn- 29(Ni+Cu) — ~13.7Cr-18.5Mo (4). u. A soft duplex stainless steel wire having excellent cold workability, which is excellent in cold workability according to claim 10, which contains M〇: 3.〇 in mass%. /0 below. 12. The magnetization of the soft-processed mild steel of the 10th or 11th paragraph of the patent application is as follows: The soft duplex stainless steel wire of 200927956 is contained in the mass% B: 0.01% or less. 13. The soft duplex stainless steel wire with excellent cold workability, which is excellent in cold workability, is contained in mass%: 8%: 0.1% or less; » Mg: 0.01% or less; and Ca : One or more of 0.01% or less. 14. The soft duplex stainless steel wire with magnetization properties, which is excellent in cold workability in the application of Patent No. 10 or 11, is contained in mass%: Nb: 1.0% or less; Ti: 0.5% or less; V: 1.0% The following; and Zr: one or more of 1.0% or less. ❹ 41