A preparation process of 8-12Cr heat-resistant steel welding wire

Abstract

The present invention discloses a process for preparing 8-12Cr heat-resistant steel welding wire, which belongs to the technical field of welding materials. The process includes a wire rod rough drawing process: Φ5.5mm-Φ(3.8-4.2)mm, a reduction rate of ≤40% for each pass, and a drawing speed of 10-220m / min; a protective atmosphere annealing process: a temperature of 700-800℃, a holding time of 1-5h; a fine drawing process: Φ(3.8-4.2)mm-Φ(2.0-2.4)mm, a reduction rate of ≤35% for each pass, and a drawing speed of 10-18 ... Temperature: 700-800°C, holding time: 1-5h; finishing process: Φ(2.0-2.4)mm-Φ1.2mm, reduction rate of each pass ≤30%, drawing speed 10-160m / min; wire breakage during the drawing process; apparent properties of the welding wire: diameter deviation: -0.03-+0.01mm, relaxed diameter: Φ750-Φ1000mm, warp: ≤5mm, tensile strength: ≥930MPa, stable wire feeding process, and good process performance.

Description

Technical Field

[0001] The present invention relates to the technical field of welding materials, and in particular to a preparation process of an 8-12Cr heat-resistant steel welding wire. The welding wire is used for welding structural parts used in high-temperature environments. Background Art

[0002] Heat-resistant steel is generally required to possess high-temperature strength, oxidation resistance, and corrosion resistance, making it an important candidate material for high-temperature components of fourth-generation fast reactors. In addition to requiring high-temperature strength and resistance to high-temperature oxidation and corrosion, these components also require sufficient toughness, good machinability, a certain degree of structural stability, and good weldability, depending on their intended use. Welding is a key thermal processing process in the manufacture of heat-resistant steel components for fourth-generation fast reactors, and welded joints are one of the primary locations for component failure during service. Numerous factors influence the quality of welded joints, affecting not only the properties and weldability of the parent material but also the performance of the welding material. Therefore, improving the R&D capabilities and manufacturing capabilities of heat-resistant steel welding materials, strictly controlling the manufacturing process of welding materials, and ensuring the stable performance of each batch of welding materials are the prerequisites and foundation for maintaining the manufacturing quality of heat-resistant steel components.

[0003] At present, the drawing process in the preparation of heat-resistant steel welding wire is complicated and requires repeated intermediate annealing processes, which results in high production costs, high labor intensity, and long delivery cycle. In addition, the processes used by different manufacturers are different. Even if the same manufacturer produces different batches of heat-resistant steel welding materials, the production processes are different. As a result, the performance of heat-resistant steel welding wires produced by different manufacturers or different batches of the same manufacturer varies greatly, which is not conducive to the stable welding and manufacturing of subsequent heat-resistant steel components. In order to solve the above problems, a special drawing process is developed for 8-12Cr heat-resistant steel welding wire. By reasonably designing the pass reduction, the number of intermediate annealing times can be reduced to improve product quality and stability and reduce production costs. Summary of the Invention

[0004] In order to solve the problems such as the uncertainty of the preparation process of heat-resistant steel welding wire, which leads to unstable performance of different batches of welding wire, the purpose of the present invention is to provide a preparation process of 8-12Cr heat-resistant steel welding wire, which is suitable for welding heat-resistant steel structural components in high-temperature service environment.

[0005] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0006] A process for preparing 8-12Cr heat-resistant steel welding wire comprises the following steps: rough drawing, protective atmosphere annealing, fine drawing, protective atmosphere annealing, and finish drawing are sequentially performed on 8-12Cr heat-resistant steel Φ5.5mm wire rods to complete the drawing of the welding wire.

[0007] The chemical composition of the 8-12Cr heat-resistant steel welding wire, calculated by weight percentage, is as follows: C: 0.04-0.16%, Cr: 8.0-12.0%, Si: 0.20-1.80%, Ni: 0.2-2.2%, Mo: 0.2-1.8%, N: 0.02-0.15%, Nb: 0.02-0.15%, V: 0.05-0.30%, Mn: 0.20-2.50%; the balance is iron and unavoidable impurities.

[0008] The Φ5.5mm wire rod is subjected to a rough drawing process: Φ5.5mm wire rod-Φ(3.8-4.2)mm intermediate wire, the pass reduction rate is ≤40%, and the drawing speed is 10-220m / min.

[0009] The Φ (3.8 ~ 4.2) mm intermediate wire is subjected to offline annealing treatment: using pure Ar gas protection, annealing temperature 700-800 ° C, holding time 1-5 hours, and furnace cooling.

[0010] The Φ (3.8 ~ 4.2) mm intermediate wire is subjected to a fine drawing process: Φ (3.8 ~ 4.2) mm intermediate wire-Φ (2.0 ~ 2.4) mm intermediate wire, the pass reduction rate is ≤ 35%, and the drawing speed is 10-180 m / min.

[0011] The Φ (2.0 ~ 2.4) mm intermediate wire is subjected to offline annealing treatment: using pure Ar gas protection, annealing temperature 700-800 ° C, holding time 1-5 hours, and furnace cooling.

[0012] The Φ (2.0 ~ 2.4) mm intermediate wire is subjected to a fine drawing process: Φ (2.0 ~ 2.4) mm-Φ 1.2 mm welding wire, the pass reduction rate is ≤ 30%, and the drawing speed is 10-160 m / min.

[0013] The welding wire of the present invention does not break during the drawing process, and has the following apparent properties: diameter deviation -0.03 to +0.01 mm, relaxation diameter Φ750 to Φ1000 mm, warp distance ≤5 mm, welding wire tensile strength ≥930 MPa, stable wire feeding process, and good process performance.

[0014] The present invention has the following advantages:

[0015] 1. Experimental verification shows that the 8-12Cr heat-resistant steel welding wire produced by the present invention is suitable for welding heat-resistant steel structural components in high-temperature service environments.

[0016] 2. The present invention can prevent wire breakage during the drawing process.

[0017] 3. The apparent properties of the 8-12Cr heat-resistant steel welding wire produced by the present invention meet the following requirements: diameter deviation -0.03 to +0.01 mm, relaxed diameter Φ750 to Φ1000 mm, warpage ≤5 mm, and welding wire tensile strength ≥930 MPa.

[0018] 4. When the 8-12Cr heat-resistant steel welding wire produced by the present invention is used for welding, the wire feeding process is stable and the process performance is good. DETAILED DESCRIPTION

[0019] The 8-12Cr heat-resistant steel welding wire of the present invention can be drawn on a steel welding wire drawing production line. The present invention will be further described in detail below with reference to specific embodiments, but this does not constitute any limitation to the present invention. The described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without inventive work shall fall within the scope of protection of the present invention.

[0020] Example 1:

[0021] Rough drawing process: 5.5mm-4.9mm-4.4mm-4.0mm, a total of three passes, with reduction ratios of 20.6%, 19.4%, and 17.4% for each pass, respectively. Drawing speed: 140m / min. Intermediate wire offline annealing process: pure Ar gas protection, temperature 760℃, hold for 2 hours, furnace cooling. Fine drawing process: 4.0mm-3.4mm-2.9mm-2.5mm-2.2mm, a total of four passes, with reduction ratios of 27.8%, 27.2%, 25.7%, and 22.6% for each pass, respectively. Drawing speed: 100 m / min; intermediate wire offline annealing process: pure Ar gas shielding, temperature: 760°C, hold temperature: 2 h, furnace cooling; finishing process: 2.2 mm - 1.9 mm - 1.65 mm - 1.45 mm - 1.3 mm - 1.2 mm, a total of 5 passes, with reduction ratios of 25.4%, 24.6%, 22.8%, 19.6%, and 14.8% respectively; drawing speed: 80 m / min. Drawing conditions and apparent wire properties are shown in Table 1.

[0022] Example 2:

[0023] Rough drawing process: 5.5mm-4.9mm-4.4mm-4.0mm, a total of 3 passes, with reduction ratios of 20.6%, 19.4%, and 17.4% respectively. Drawing speed 140m / min. Intermediate wire offline annealing process: pure Ar gas protection, temperature 760℃, hold for 2 hours, furnace cooling. Fine drawing process: 4.0mm-3.55mm-3.05mm-2.75mm-2.45mm-2.2mm, a total of 5 passes, with reduction ratios of 21.2%, 27.9%, 14.2%, 20.6%, and 19.4% respectively. Drawing speed: 110 m / min; intermediate wire offline annealing process: pure Ar gas shielding, temperature: 780°C, hold temperature: 3 hours, furnace cooling; finishing process: 2.2 mm - 1.9 mm - 1.65 mm - 1.45 mm - 1.3 mm - 1.2 mm, a total of 5 passes, with reduction ratios of 25.4%, 24.6%, 22.8%, 19.6%, and 14.8% respectively, and drawing speed: 60 m / min. Drawing conditions and apparent wire properties are shown in Table 1.

[0024] Example 3:

[0025] Rough drawing process: 5.5mm-5.1mm-4.7mm-4.4mm-4.0mm, a total of 4 passes, with reduction ratios of 14.0%, 15.1%, 12.4%, and 17.4% for each pass. Drawing speed: 140m / min. Intermediate wire offline annealing process: pure Ar gas protection, temperature 750℃, hold for 3 hours, furnace cooling. Fine drawing process: 4.0mm-3.4mm-2.9mm-2.5mm-2.2mm, a total of 4 passes, with reduction ratios of 27.8%, 27.2%, 25.7%, and 22.6% for each pass. Drawing speed: 100 m / min; intermediate wire offline annealing process: pure Ar gas shielding, temperature: 760°C, hold temperature: 2 h, furnace cooling; finishing process: 2.2 mm - 1.9 mm - 1.65 mm - 1.45 mm - 1.3 mm - 1.2 mm, a total of 5 passes, with reduction ratios of 25.4%, 24.6%, 22.8%, 19.6%, and 14.8% respectively; drawing speed: 80 m / min. Drawing conditions and apparent wire properties are shown in Table 1.

[0026] Example 4:

[0027] Rough drawing process: 5.5mm-4.9mm-4.4mm-4.0mm, a total of three passes, with reduction ratios of 20.6%, 19.4%, and 17.4% for each pass, respectively. Drawing speed: 140m / min. Intermediate wire offline annealing process: pure Ar gas protection, temperature 760℃, hold for 2 hours, furnace cooling. Fine drawing process: 4.0mm-3.4mm-2.9mm-2.5mm-2.2mm, a total of four passes, with reduction ratios of 27.8%, 27.2%, 25.7%, and 22.6% for each pass, respectively. Drawing speed: 100 m / min; intermediate wire offline annealing process: pure Ar gas shielding, temperature: 750°C, hold temperature: 2 h, furnace cooling; finishing process: 2.2 mm - 1.95 mm - 1.75 mm - 1.55 mm - 1.4 mm - 1.3 mm - 1.2 mm, totaling 6 passes, with reduction ratios of 21.4%, 19.5%, 21.6%, 18.4%, 13.8%, and 14.7% respectively; drawing speed: 70 m / min. Drawing conditions and wire apparent properties are shown in Table 1.

[0028] Comparative Example 1:

[0029] Rough drawing process: 5.5mm-4.9mm-4.4mm-4.0mm, a total of 3 passes, with reduction ratios of 20.6%, 19.4%, and 17.4% respectively. Drawing speed 140m / min. Intermediate wire offline annealing process: pure Ar gas protection, temperature 670℃, hold temperature 0.5h, furnace cooling. Fine drawing process: 4.0mm-3.3mm-2.9mm-2.5mm-2.2mm, a total of 4 passes, with reduction ratios of 31.9%, 22.8%, 25.7%, and 22.6% respectively. Drawing speed: 100 m / min; intermediate wire offline annealing process: pure Ar gas shielding, temperature: 760°C, hold temperature: 2 h, furnace cooling; finishing process: 2.2 mm - 1.9 mm - 1.65 mm - 1.45 mm - 1.3 mm - 1.2 mm, a total of 5 passes, with reduction ratios of 25.4%, 24.6%, 22.8%, 19.6%, and 14.8% respectively; drawing speed: 80 m / min. Drawing conditions and apparent wire properties are shown in Table 1.

[0030] Comparative Example 2:

[0031] Rough drawing process: 5.5mm-4.9mm-4.4mm-4.0mm, a total of 3 passes, with reduction ratios of 20.6%, 19.4%, and 17.4% respectively. Drawing speed 140m / min. Intermediate wire offline annealing process: pure Ar gas protection, temperature 740℃, hold temperature 2.0h, furnace cooling. Fine drawing process: 4.0mm-3.5mm-3.1mm-2.4mm-2.2mm, a total of 4 passes, with reduction ratios of 23.4%, 21.6%, 40.1%, and 16.0% respectively. Drawing speed: 100 m / min; intermediate wire offline annealing process: pure Ar gas shielding, temperature: 760°C, hold temperature: 2 h, furnace cooling; finishing process: 2.2 mm - 1.9 mm - 1.65 mm - 1.45 mm - 1.3 mm - 1.2 mm, a total of 5 passes, with reduction ratios of 25.4%, 24.6%, 22.8%, 19.6%, and 14.8% respectively; drawing speed: 80 m / min. Drawing conditions and apparent wire properties are shown in Table 1.

[0032] Comparative Example 3:

[0033] Rough drawing process: 5.5mm-4.9mm-4.4mm-4.0mm, a total of three passes, with reduction ratios of 20.6%, 19.4%, and 17.4% for each pass, respectively. Drawing speed: 140m / min. Intermediate wire offline annealing process: pure Ar gas protection, temperature 760℃, hold for 2 hours, furnace cooling. Fine drawing process: 4.0mm-3.4mm-2.9mm-2.5mm-2.2mm, a total of four passes, with reduction ratios of 27.8%, 27.2%, 25.7%, and 22.6% for each pass, respectively. Drawing speed: 100 m / min; intermediate wire offline annealing: pure Ar gas shielding, temperature: 760°C, hold for 2 hours, furnace cooling; finishing drawing: 2.2 mm - 1.9 mm - 1.7 mm - 1.3 mm - 1.2 mm, four passes, with reduction ratios of 25.4%, 19.9%, 41.5%, and 14.8% respectively; drawing speed: 90 m / min. Drawing conditions and wire apparent properties are shown in Table 1.

[0034] Table 1 Drawing conditions and apparent properties of welding wires of the embodiment and comparative example

[0035]

[0036]

[0037] The present invention can ensure that the 8-12Cr heat-resistant steel welding wire is not broken during the drawing process, and the apparent performance of the welding wire meets the following requirements: diameter deviation -0.03 to +0.01 mm, relaxation diameter Φ750 to Φ1000 mm, warp distance ≤5 mm, welding wire tensile strength ≥930 MPa, and the wire feeding process is stable and the process performance is good.

[0038] From Examples 1-4, Comparative Examples 1-3 and Table 1, it can be seen that:

[0039] Using the wire drawing process designed by the present invention, Examples 1-4 meet the design requirements of the present invention. In Comparative Example 1, the offline annealing temperature of the intermediate wire after rough drawing is relatively low and the time is relatively short, namely 670°C and 0.5h, respectively, which is not within the scope of the technical solution of the present invention (temperature 700-800°C, holding time 1-5h). The work hardening structure formed by rough drawing is not fully recovered, resulting in wire breakage during the fine drawing process; in Comparative Example 2, the pass reduction rate in the fine drawing process is 40.1%, which is not within the scope of the technical solution of the present invention (reduction rate ≤35%), and wire breakage occurs during the fine drawing process. In Comparative Example 3, the pass reduction rate in the fine drawing process is 41.5%, which is not within the scope of the technical solution of the present invention (reduction rate ≤30%), and wire breakage occurs during the fine drawing process.

Claims

1. A process for preparing 8-12Cr heat-resistant steel welding wire, characterized by: The process is to carry out rough drawing, protective atmosphere annealing, fine drawing, protective atmosphere annealing, and finish drawing of 8-12Cr heat-resistant steel Φ5.5mm wire rod in sequence to complete the wire drawing; The rough drawing process is to draw the Φ5.5mm wire rod into the Φ(3.8-4.2)mm intermediate wire, with a pass reduction rate of ≤40% and a drawing speed of 10-220m / min; The Φ (3.8 ~ 4.2) mm intermediate wire is subjected to offline annealing treatment, using pure Ar gas protection, annealing temperature 700-800 ℃, holding time 1-5h, and furnace cooling; The annealed Φ (3.8 ~ 4.2) mm intermediate wire is subjected to a fine drawing process, and the Φ 3.8 ~ 4.2 mm intermediate wire is drawn to Φ (2.0 ~ 2.4) mm intermediate wire, with a pass reduction rate of ≤ 35% and a drawing speed of 10-180 m / min; The Φ (2.0 ~ 2.4) mm intermediate wire is subjected to offline annealing treatment, using pure Ar gas protection, annealing temperature 700-800 ℃, holding time 1-5h, and furnace cooling; The annealed Φ (2.0 ~ 2.4) mm intermediate wire is subjected to a fine drawing process to draw the Φ (2.0 ~ 2.4) mm intermediate wire into a Φ 1.2 mm welding wire, with a pass reduction rate of ≤ 30% and a drawing speed of 10-160 m / min.

2. The process for preparing the 8-12Cr heat-resistant steel welding wire according to claim 1, wherein: The chemical composition of the welding wire is as follows, by weight percentage: C: 0.04-0.16%, Cr: 8.0-12.0%, Si: 0.20-1.80%, Ni: 0.2-2.2%, Mo: 0.2-1.8%, N: 0.02-0.15%, Nb: 0.02-0.15%, V: 0.05-0.30%, Mn: 0.20-2.50%; the balance is iron and inevitable impurities.

3. The process for preparing the 8-12Cr heat-resistant steel welding wire according to claim 1, wherein: The welding wire is not broken during the drawing process, and the apparent properties of the welding wire are as follows: diameter deviation is -0.03 to +0.01 mm, relaxation diameter is Φ750 to Φ1000 mm, warpage is ≤5 mm, welding wire tensile strength is ≥930 MPa, and the wire feeding process is stable, with good process performance.

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