A method for manufacturing large forgings to ensure flaw detection and performance of 1010 steel

Abstract

The invention discloses a method for manufacturing large forgings that ensures ultrasonic flaw detection performance and use performance of 1010 steel, belongs to the technical field of large forging manufacturing, and comprises the following steps: S10, microalloying with aluminum element on the basis of conventional composition of 1010 steel; S20, multi-fire forging with multiple fires by sequentially lowering the initial forging temperature and the final forging temperature; S30, annealing treatment that satisfies the use performance of 1010 steel large forgings after forging. The invention obtains a method for manufacturing large forgings that ensures ultrasonic flaw detection performance and use performance of 1010 steel by designing microalloying Al element on the composition of 1010 steel large forgings and adopting low initial forging temperature and final forging temperature of the last fire forging and ensuring the forging deformation amount ≥30%.

Description

Technical Field

[0001] The invention belongs to the technical field of large forging manufacturing, and in particular relates to a manufacturing method of large forgings which can ensure the ultrasonic flaw detection performance and use performance of 1010 steel. Background Art

[0002] ASTMA291010 steel is equivalent to my country's No. 10 steel (Fe-0.1C). It has a low degree of alloying, and there is no precipitation of C and N compounds formed by elements such as Nb, V, and Ti, nor solid solution of elements such as Cr, Ni, and Mo. The grains tend to grow greatly during forging and heat treatment. In particular, in some special cases, in order to ensure certain specific performance, annealing treatment at 900°C and heat preservation for more than 7 hours after forging must be carried out. These lead to serious coarsening of the grains, and the screen is full of clutter during ultrasonic flaw detection, which cannot meet the performance requirements of ultrasonic flaw detection.

[0003] Forging process is also extremely important for the ultrasonic flaw detection performance of large forgings. There is a critical deformation for the plastic deformation of metal materials. If the deformation is lower than the critical deformation, recrystallization and grain refinement will not occur. On the contrary, grain coarsening and mixed crystal phenomena will occur, which will seriously deteriorate the organizational properties of the material and cause ultrasonic flaw detection to fail.

[0004] So far, there is no method available for manufacturing large forgings that can guarantee the ultrasonic flaw detection performance and performance of 1010 steel, which to a certain extent restricts the development of my country's aerospace, weapon equipment and other industries. Summary of the invention

[0005] The purpose of the present invention is to obtain a method for manufacturing large forgings that ensures the ultrasonic flaw detection performance and service performance of 1010 steel by organically integrating the composition design and forging process of 1010 steel large forgings. The technical solution adopted by the present invention is:

[0006] A method for manufacturing large forgings that ensures flaw detection and performance of 1010 steel, comprising the following steps:

[0007] S10, microalloying with aluminum on the basis of the conventional composition of 1010 steel;

[0008] S20, performing multi-fire forging in multiple times by sequentially lowering the initial forging temperature and the final forging temperature;

[0009] S30: After forging, annealing treatment is performed to meet the performance requirements of 1010 steel large forgings.

[0010] Furthermore, in step S20, multi-fire forging is performed for 5 to 6 times by sequentially lowering the initial forging temperature and the final forging temperature.

[0011] Further, in step S20, when multi-fire forging is performed for 5 times, 1 fire of high-temperature deformation is performed for blanking, the initial forging temperature is 1100-1200°C, and the final forging temperature is 500-600°C; secondly, 2 fires of high-temperature deformation upsetting and squaring are performed, the initial forging temperature is 1100-1200°C, and the final forging temperature is 500-600°C; then, 1 fire of drawing-rounding low-temperature pre-forming is performed, the initial forging temperature is 850-950°C, and the final forging temperature is 500-600°C; finally, 1 fire of local upsetting and final forming of the mold is performed, the initial forging temperature is 850-950°C, the final forging temperature is 400-500°C, and the deformation amount is ≥30%.

[0012] Further, in step S20, when the multi-fire forging is performed for 6 times, 1 fire of high temperature deformation is performed for blanking, the initial forging temperature is 1100-1200°C, and the final forging temperature is 500-600°C; secondly, 1 fire of high temperature deformation upsetting and square drawing is performed, the initial forging temperature is 1100-1200°C, and the final forging temperature is 500-600°C; then, 3 fires of ring forging rounding-punching-expanding, rounding-drawing, and along The medium-temperature preforming by upsetting in the length direction has the initial forging temperatures of 1050-1150°C, 1050-1150°C, 1000-1100°C, and the final forging temperatures of 500-600°C, 500-600°C, and 400-500°C, respectively; finally, the low-temperature final forming of the ring forging by 1-fire hole expansion-rounding is carried out, with the initial forging temperature of 850-950°C, the final forging temperature of 400-500°C, and the deformation amount ≥30%.

[0013] Furthermore, in step S30, the annealing temperature of the annealing treatment is 850-1150°C.

[0014] Further, 1010 steel heavy forgings contain iron, aluminum, carbon, silicon and manganese components.

[0015] Furthermore, the mass percentage of aluminum is 0.022-0.025%, the mass percentage of carbon is 0.06-0.1%, the mass percentage of silicon is 0.20-0.30%, the mass percentage of manganese is 0.43-0.45%, and the rest is iron and impurity elements.

[0016] Furthermore, the mass percentage of carbon is 0.08%, and the mass percentage of silicon is 0.24%.

[0017] Furthermore, the impurity element is ≤0.03%.

[0018] Beneficial effects of the present invention:

[0019] (1) The present invention obtains a method for manufacturing large forgings that ensures the ultrasonic flaw detection performance and service performance of 1010 steel by designing the Al element microalloying for the composition of the large forgings of 1010 steel, adopting low initial forging temperature and final forging temperature of the last forging, and ensuring that the forging deformation is ≥30%.

[0020] (2) The present invention prevents the grain growth of the forging by microalloying Al element in the 1010 steel large forging using the insoluble compounds formed by Al element.

[0021] (3) The present invention provides a prerequisite for obtaining ideal performance and grain size structure in subsequent annealing treatment by adopting low initial forging temperature and final forging temperature of the last forging and ensuring that the forging deformation is ≥30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a diagram of an ultrasonic flaw detection forging according to Example 1 of the present invention;

[0023] Figure 2 is a waveform diagram of an ultrasonic flaw detection forging according to Example 1 of the present invention;

[0024] Figure 3 is a diagram of an ultrasonic flaw detection forging according to Example 2 of the present invention;

[0025] Figure 4 is a waveform diagram of an ultrasonic flaw detection forging according to Example 2 of the present invention;

[0026] Figure 5 This is a diagram of an ultrasonic flaw detection forging of Comparative Example 1 of the present invention;

[0027] Figure 6 is a waveform diagram of the ultrasonic flaw detection forging of Comparative Example 1 of the present invention;

[0028] Figure 7 The present invention discloses a flow chart of a method for manufacturing a large forging that ensures the ultrasonic flaw detection performance and service performance of 1010 steel. DETAILED DESCRIPTION

[0029] The present invention provides a method for manufacturing a large forging that ensures the flaw detection and service performance of 1010 steel, comprising the following steps:

[0030] S10, microalloying with aluminum on the basis of the conventional composition of 1010 steel;

[0031] S20, performing multi-fire forging in multiple times by sequentially lowering the initial forging temperature and the final forging temperature;

[0032] S30: After forging, annealing treatment is performed to meet the performance requirements of 1010 steel large forgings.

[0033] In the present invention, in step S20, when multi-fire forging is performed for 5 times, 1 fire of high-temperature deformation is performed for blanking, the initial forging temperature is 1100-1200°C, and the final forging temperature is 500-600°C; secondly, 2 fires of high-temperature deformation upsetting and square drawing are performed, the initial forging temperature is 1100-1200°C, and the final forging temperature is 500-600°C; then, 1 fire of drawing-rounding low-temperature pre-forming is performed, the initial forging temperature is 850-950°C, and the final forging temperature is 500-600°C; finally, 1 fire of local mold upsetting and final forming is performed, the initial forging temperature is 850-950°C, the final forging temperature is 400-500°C, and the deformation amount is ≥30%.

[0034] Among them, the first fire high temperature deformation is carried out, and the initial forging temperature and the final forging temperature are 1100-1200°C and 500-600°C, respectively, preferably 1140-1160°C and 540-560°C, and more preferably 1145-1155°C and 545-555°C;

[0035] Perform 2-fire high-temperature deformation upsetting and square drawing, the initial forging temperature and the final forging temperature are 1100-1200°C and 500-600°C, respectively, preferably 1140-1160°C and 540-560°C, more preferably 1145-1155°C and 545-555°C;

[0036] The initial forging temperature and final forging temperature of the low-temperature preforming of the first fire drawing-rounding are 850-950°C and 500-600°C, preferably 880-910°C and 540-560°C, and more preferably 885-905°C and 545-555°C;

[0037] The initial forging temperature and final forging temperature for the partial upsetting and final forming of the single-fire die are 850-950°C and 400-500°C, respectively, preferably 880-910°C and 440-460°C, and more preferably 885-905°C and 445-455°C.

[0038] In the present invention, in step S20, when the multi-fire forging is performed for 6 times, 1 fire of high temperature deformation is performed for blanking, the initial forging temperature is 1100-1200°C, and the final forging temperature is 500-600°C; secondly, 1 fire of high temperature deformation upsetting and square drawing is performed, the initial forging temperature is 1100-1200°C, and the final forging temperature is 500-600°C; then, 3 fires of ring forging rounding-punching-expanding, rounding-lengthening, and along The medium-temperature preforming by upsetting in the length direction has the initial forging temperatures of 1050-1150°C, 1050-1150°C, 1000-1100°C, and the final forging temperatures of 500-600°C, 500-600°C, and 400-500°C, respectively; finally, the low-temperature final forming of the ring forging by 1-fire hole expansion-rounding is carried out, with the initial forging temperature of 850-950°C, the final forging temperature of 400-500°C, and the deformation amount ≥30%.

[0039] Among them, the first fire high temperature deformation is carried out, and the initial forging temperature and the final forging temperature are 1100-1200°C and 500-600°C, respectively, preferably 1160-1190°C and 540-560°C, and more preferably 1175-1185°C and 545-555°C;

[0040] Performing high temperature deformation upsetting and square drawing in one fire, the initial forging temperature and the final forging temperature are 1100-1200°C and 500-600°C, respectively, preferably 1160-1190°C and 540-560°C, more preferably 1175-1185°C and 545-555°C;

[0041] The initial forging temperatures for the 3-fire ring forgings of rolling-punching-expanding, rolling-drawing, and medium-temperature preforming by upsetting along the length direction are 1050-1150°C, 1050-1150°C, 1000-1100°C, preferably 1080-1150°C, 1080-1150°C, 1040-1050°C, and more preferably 1090-1100°C, 1090-1100°C, 1045-1050°C; the final forging temperatures are 500-600°C, 500-600°C, 400-500°C, preferably 520-560°C, 520-560°C, 440-460°C, and more preferably 545-555°C, 545-555°C, 445-455°C.

[0042] The initial forging temperature and final forging temperature for the low-temperature final forming of the 1-fire ring forging hole expansion-rounding are 850-950°C and 400-500°C, respectively, preferably 880-910°C and 440-460°C, and further preferably 885-905°C and 445-455°C.

[0043] In the present invention, in step S30, the annealing temperature of the annealing treatment is 850-1150°C, preferably 880-910°C, and more preferably 890-905°C.

[0044] In the present invention, the 1010 steel heavy forging contains iron, aluminum, carbon, silicon and manganese components.

[0045] Among them, the mass percentage of aluminum is 0.022-0.025%; the mass percentage of carbon is 0.06-0.1%, preferably 0.08%; the mass percentage of silicon is 0.20-0.30%, preferably 0.24%; the mass percentage of manganese is 0.43-0.45%; the rest is iron and impurity elements, among which the impurity elements are preferably ≤0.03%.

[0046] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0047] Example 1

[0048] A large forging (solid forging, such as 1010 steel) that guarantees the ultrasonic flaw detection performance and service performance Figure 1 The manufacturing method of the present invention comprises the following steps:

[0049] S10. According to the composition design requirements, a 28-ton 1010 steel ingot is produced by electric furnace smelting + refining outside the furnace + vacuum degassing. The chemical composition (mass percentage) detected by spectrometer is as follows: the mass percentage of aluminum (Al) is 0.022%, the mass percentage of carbon (C) is 0.08%, the mass percentage of silicon (Si) is 0.24%, the mass percentage of manganese (Mn) is 0.43%, and the rest is iron and a small amount of impurity elements, and the impurity elements are ≤0.03%.

[0050] Microalloying Al into 1010 steel, where Al and Fe form insoluble compounds such as FeAl, can effectively regulate the grain structure of 1010 steel, refine the dynamically recrystallized grains of forgings, and prevent the growth of recrystallized grains during post-forging heat treatment.

[0051] S20, performing 5-fire forging with the initial forging temperature and the final forging temperature decreasing in sequence, with a total forging ratio of 17.6.

[0052] First, one fire of high-temperature deformation is carried out to open the blank, with the initial forging temperature of 1150℃ and the final forging temperature of 550℃; secondly, two fires of high-temperature deformation upsetting and square drawing are carried out, with the initial forging temperature of 1150℃ and the final forging temperature of 550℃; then, one fire of low-temperature pre-forming (drawing-rounding) is carried out, with the initial forging temperature of 900℃ and the final forging temperature of 550℃; finally, one fire of final forming (partial upsetting of the mold) is carried out, with the initial forging temperature of 900℃ and the final forging temperature of 450℃, and the deformation amount is ≥30%.

[0053] S30: perform annealing treatment to meet the performance requirements of 1010 steel large forgings, with the annealing temperature being 900°C.

[0054] Among them, the annealing time is calculated according to the thickness of the forging, and the insulation time is 3 hours for every 100mm thickness.

[0055] That is, a large forging (solid forging) is obtained which guarantees the ultrasonic flaw detection performance and service performance of 1010 steel.

[0056] The 1010 steel large forgings (solid forgings) manufactured by the above steps are tested according to the flaw detection standard GB / T6402-2008 level 3 using ultrasonic flaw detector CTS-2020 (probe 2P20Z, straight probe, wafer effective diameter Φ20, probe nominal frequency 2MHz). The flaw detection results are: Φ3 sensitivity, good bottom wave reflection, maximum bottom wave reduction less than 6dB, no related defects, and ultrasonic flaw detection is qualified at one time ( Figure 2 ).

[0057] Example 2

[0058] A large forging (large cross-section ring forging, such as 1010 steel) that guarantees the ultrasonic flaw detection performance and service performance Figure 3 As shown, the manufacturing method of the outer diameter is 3090mm, the inner diameter is 1640mm, and the height is 800mm), and the manufacturing process includes the following steps:

[0059] S10. According to the composition design requirements, a 1010 steel ingot weighing 42 tons was refined by electric furnace smelting + refining outside the furnace + vacuum degassing. The chemical composition (mass percentage) detected by spectrometer is as follows: the mass percentage of aluminum (Al) is 0.022%, the mass percentage of carbon (C) is 0.08%, the mass percentage of silicon (Si) is 0.24%, the mass percentage of manganese (Mn) is 0.43%, and the rest is iron and a small amount of impurity elements, and the impurity elements are ≤0.03%.

[0060] Microalloying Al into 1010 steel, where Al and Fe form insoluble compounds such as FeAl, can effectively regulate the grain structure of 1010 steel, refine the dynamically recrystallized grains of forgings, and prevent the growth of recrystallized grains during post-forging heat treatment.

[0061] S20, performing 6-fire forging with the initial forging temperature and the final forging temperature being lowered in sequence, with a total forging ratio of 5.

[0062] First, one fire of high-temperature deformation is carried out to open the blank, with the initial forging temperature being 1180℃ and the final forging temperature being 550℃; secondly, one fire of high-temperature deformation upsetting and square drawing is carried out, with the initial forging temperature being 1180℃ and the final forging temperature being 550℃; then, three fires of medium-temperature preforming of annular forgings (rounding-punching-hole expansion, rounding-drawing, and upsetting along the length direction) are carried out, with the initial forging temperatures being 1100℃, 1100℃, and 1050℃, and the final forging temperatures being 550℃, 550℃, and 450℃, respectively; finally, one fire of low-temperature final forming of annular forgings (hole expansion-rounding) is carried out, with the initial forging temperature being 900℃ and the final forging temperature being 450℃, and the deformation amount being ≥30%.

[0063] S30, perform annealing treatment to meet the performance requirements of 1010 steel large forgings, with the annealing temperature being 900° C. The annealing time is calculated according to the thickness of the forgings, and the heat preservation time is 3 hours for every 100 mm thickness.

[0064] That is, a large forging (large cross-section ring forging) is obtained which guarantees the ultrasonic flaw detection performance and service performance of 1010 steel.

[0065] The 1010 steel large-section annular forging (outer diameter 3090mm, inner diameter 1640mm, height 800mm) manufactured by the above steps is inspected according to the flaw detection standard GB / T6402-2008 level 3, using ultrasonic flaw detector CTS-2020 (probe 2P20Z, straight probe, wafer effective diameter Φ20, probe nominal frequency 2MHz). The flaw detection results are: Φ3 sensitivity, good bottom wave reflection, clutter less than 30%, maximum bottom wave reduction less than 6dB, no related defects, and ultrasonic flaw detection is qualified at one time ( Figure 4 ).

[0066] Comparative Example 1

[0067] A large forging (solid forging, such as Figure 5 The manufacturing method of the present invention comprises the following steps:

[0068] S10. According to the composition design requirements, a 1010 steel ingot weighing 29.5 tons was refined by electric furnace smelting + refining outside the furnace + vacuum degassing. The chemical composition (mass percentage) detected by spectrometer is: the mass percentage of aluminum (Al) is 0.01%, the mass percentage of carbon (C) is 0.07%, the mass percentage of silicon (Si) is 0.22%, the mass percentage of manganese (Mn) is 0.45%, and the rest is iron and a small amount of impurity elements.

[0069] S20, perform three-fire forging with the initial forging temperature and the final forging temperature decreasing in sequence, with a total forging ratio of 21.8.

[0070] First, one fire of high-temperature deformation is carried out to open the blank, with the initial forging temperature of 1150℃ and the final forging temperature of 650℃; secondly, one fire of high-temperature deformation upsetting and square drawing is carried out, with the initial forging temperature of 1150℃ and the final forging temperature of 650℃; finally, one fire of final forming (upsetting-square drawing-upsetting-rounding-partial upsetting of the mold) is carried out, with the initial forging temperature of 1000℃ and the final forging temperature of 550℃, and the deformation amount is ≥30%.

[0071] S30, perform annealing treatment to meet the performance requirements of 1010 steel large forgings, with the annealing temperature being 900° C. The annealing time is calculated according to the thickness of the forgings, and the heat preservation time is 3 hours for every 100 mm thickness.

[0072] That is, a large forging (solid forging) is obtained which cannot guarantee the ultrasonic flaw detection performance of 1010 steel.

[0073] The 1010 steel large forging (solid forging) manufactured by the above steps is inspected according to the flaw detection standard GB / T6402-2008 level 3, using ultrasonic flaw detector CTS-2020 (probe 1.25P20Z, straight probe, wafer effective diameter Φ20, probe nominal frequency 1.25MHz). The flaw detection result is: Φ3 sensitivity. Although the probe frequency is reduced, the screen is still full of clutter, and the maximum bottom wave reduction is 20dB, which cannot meet the flaw detection requirements ( Figure 6 ).

[0074] The present invention does not involve parts that are the same as the prior art or can be implemented by using the prior art.

[0075] The above fully describes the technical solution of the present invention. It should be noted that the specific implementation of the present invention is not limited to the above description. All technical solutions formed by ordinary technicians in the field using equivalent or equivalent transformations in structure, method or function based on the spirit of the present invention fall within the protection scope of the present invention.

Claims

1. A method for manufacturing large forgings to ensure flaw detection and performance of 1010 steel, characterized in that: The following steps are involved: S10, based on the conventional composition of 1010 steel, aluminum is used for microalloying, and the mass percentage of aluminum is 0.022~0.025%; S20, performing multi-fire forging in multiple times by sequentially lowering the initial forging temperature and the final forging temperature; S30, after forging, annealing treatment is performed to meet the performance requirements of 1010 steel large forgings; In step S20, multi-fire forging is performed for 5 to 6 times by sequentially lowering the initial forging temperature and the final forging temperature; When multi-fire forging is performed for 5 times, the first fire is high-temperature deformation and blanking, the initial forging temperature is 1100~1200℃, and the final forging temperature is 500~600℃; secondly, the second fire is high-temperature deformation upsetting and drawing, the initial forging temperature is 1100~1200℃, and the final forging temperature is 500~600℃; then, the first fire is drawn and rounded low-temperature pre-forming, the initial forging temperature is 850~950℃, and the final forging temperature is 500~600℃; finally, the first fire is die partial upsetting and final forming, the initial forging temperature is 850~950℃, the final forging temperature is 400~500℃, and the deformation amount is ≥30%; When multi-fire forging is performed for 6 times, 1 fire of high-temperature deformation is performed for blanking, the initial forging temperature is 1100~1200℃, and the final forging temperature is 500~600℃; secondly, 1 fire of high-temperature deformation upsetting and square drawing is performed, the initial forging temperature is 1100~1200℃, and the final forging temperature is 500~600℃; then, 3 fires of ring forgings are performed for rolling-punching-expanding, rolling-extension, and upsetting medium-temperature preforming along the length direction, the initial forging temperatures are 1050~1150℃, 1050~1150℃, 1000~1100℃, and the final forging temperatures are 500~600℃, 500~600℃, and 400~500℃, respectively; finally, 1 fire of ring forgings is performed for hole expansion-rolling low-temperature final forming, the initial forging temperature is 850~950℃, the final forging temperature is 400~500℃, and the deformation amount is ≥30%.

2. The method for manufacturing large forgings that ensures flaw detection and performance of 1010 steel according to claim 1, characterized in that: In step S30, the annealing temperature of the annealing treatment is 850-1150°C.

3. The method for manufacturing large forgings that ensures flaw detection and performance of 1010 steel according to claim 1, characterized in that: 1010 steel heavy forgings contain iron, aluminum, carbon, silicon and manganese.

4. The method for manufacturing large forgings that ensures flaw detection and performance of 1010 steel according to claim 3 is characterized in that: The mass percentage of carbon is 0.06~0.1%, the mass percentage of silicon is 0.20~0.30%, the mass percentage of manganese is 0.43~0.45%, and the rest is iron and impurity elements.

5. The method for manufacturing large forgings that ensures flaw detection and performance of 1010 steel according to claim 4 is characterized in that: The mass percentage of carbon is 0.08%, and the mass percentage of silicon is 0.24%.

6. The method for manufacturing large forgings that ensures flaw detection and performance of 1010 steel according to claim 4, characterized in that: The impurity elements are ≤0.03%.

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