18Ni steel intermediate alloy round bar and rolling method for ingot casting of 18Ni steel intermediate alloy round bar
By controlling rolling and surface treatment within the temperature range of 1050℃~1230℃, the problem of surface cracking of 18Ni steel intermediate alloy ingot rolled round rods is solved, and the oxygen content is effectively controlled to meet the needs of aviation, aerospace and Cleanliness requirements for high-end civilian products.
Patent Information
- Application Number
- CN202411455480.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-17
- Publication Date
- 2024-12-24
AI Technical Summary
18Ni steel intermediate alloy ingots are prone to surface cracking when rolled into round bars, resulting in excessive oxygen content and cannot meet the cleanliness requirements in the fields of aviation, aerospace and high-end civilian products.
After heating treatment, multiple pass rolling is carried out in the temperature range of 1050℃~1230℃, and the temperature of the opening and final rolling is controlled to be no less than 1180℃ and 1050℃, the single pass rolling volume is no more than 35%, and the rolling strain is The rate is 0.1 s-1~1.0 s-1, and the surface is cooled and then the rust removal treatment is carried out in the rust removal machine.
The surface cracking of the 18Ni steel intermediate alloy round rod is effectively avoided, and the oxygen content is controlled at 0.0015%-0.0018%, meeting the cleanliness requirements of aviation, aerospace and high-end civilian products for raw materials.
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Figure CN119175275A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of 18Ni steel master alloy production, in particular to a 18Ni steel master alloy round bar material and a rolling method for an ingot thereof. Background Art
[0002] In order to recycle Ni, Co, and Mo alloys, electric arc furnace (EBT) + LF furnace + VOD furnace is currently used to smelt the cut heads and iron scraps in the production process into a low C, Si, S, and P 18Ni steel special intermediate alloy. Then the intermediate alloy ingot is rolled into round bars as one of the metal raw materials, and then a vacuum induction furnace + vacuum consumable furnace is used to smelt 18Ni maraging steel ingots. 18Ni maraging steel is mainly used in the fields of aviation, aerospace, and high-end civilian products. It has extremely high requirements for the control of inclusions and gas content in the steel, so it has very high requirements for the cleanliness and gas content (H, O, N) of the raw materials.
[0003] Therefore, in order to control the oxygen content of the 18Ni steel master alloy used for smelting 18Ni maraging steel ingots, it is required that the round bars rolled from the 18Ni steel master alloy ingots should not have surface cracks. However, due to the high alloying element content of the 18Ni steel master alloy ingots, its work hardening rate is high, and the surface of the bar is particularly prone to cracking during the rolling process, which causes oxidation near the cracks inside the bar, resulting in excessively high oxygen content in the bar, which cannot meet the selection requirements for 18Ni steel raw materials in the fields of aviation, aerospace and high-end civilian products.
[0004] Therefore, it is necessary to develop a direct rolling method suitable for 18Ni steel master alloy ingots to solve the problem of surface cracking of round bars directly rolled from 18Ni steel master alloy ingots.
[0005] Based on this, the existing technology still needs to be improved. Summary of the invention
[0006] In order to solve the above technical problems, the embodiment of the present invention provides a method for rolling 18Ni steel master alloy round bars and ingots thereof, so as to solve the technical problem in the prior art that 8Ni steel master alloy ingots are prone to cracking when rolled into bars.
[0007] In order to solve the above technical problems, some embodiments of the present invention disclose a method for rolling a 18Ni steel master alloy ingot. The 18Ni intermediate alloy ingot is subjected to a heating treatment to obtain an intermediate ingot; The intermediate ingot is rolled at a temperature range of 1050° C. to 1230° C. to obtain an intermediate bar; The intermediate rod is subjected to surface treatment. In some embodiments, the heating treatment of the 18Ni master alloy ingot includes: heating the 18Ni master alloy ingot to 1200° C.-1250° C. and keeping the temperature.
[0008] In some embodiments, rolling the intermediate ingot in a temperature range of 1050°C to 1230°C includes: rolling the intermediate ingot in multiple passes with a starting rolling temperature of not less than 1180°C.
[0009] In some embodiments, rolling the intermediate ingot within a temperature range of 1050°C to 1230°C further comprises: a final rolling temperature of not less than 1050°C.
[0010] In some embodiments, rolling the intermediate ingot within a temperature range of 1050° C. to 1230° C. further comprises: a single-pass rolling amount is no greater than 35%.
[0011] In some embodiments, rolling the intermediate ingot at a temperature range of 1050° C. to 1230° C. further comprises: rolling at a strain rate of 0.1 s -1 ~1.0 s -1 .
[0012] In some embodiments, surface treatment of the intermediate rod comprises: cooling the intermediate rod to room temperature and then performing collision rust removal in a rust removal machine.
[0013] In some embodiments, the components of the 18Ni master alloy ingot include, by weight percentage: Ni: 18%-25%, Co: 8%-15%, Mo: 3.5%-5.0%, and the rest is Fe and unavoidable impurities.
[0014] In some embodiments, the preparation of the 18Ni master alloy ingot includes: electric arc furnace smelting, LF smelting, VOD furnace smelting, and pouring.
[0015] On the other hand, an embodiment of the present invention further discloses a 18Ni steel intermediate alloy round bar, which is rolled using the aforementioned 18Ni steel intermediate alloy ingot rolling method, and has no surface cracks. The oxygen content ranges from 0.0015% to 0.0018% in terms of mass percentage.
[0016] By adopting the above technical solution, the present invention has at least the following beneficial effects: The present invention provides a method for rolling a 18Ni steel master alloy round bar and an ingot thereof, wherein the surface of the obtained 18Ni steel master alloy round bar does not crack, and the oxygen content ranges from 0.0015% to 0.0018% by mass percentage. The method effectively solves the technical problem of cracking during rolling of the 18Ni master alloy ingot by effectively controlling the rolling temperature, so that the 18Ni master alloy rolled material meets the selection requirements of 18Ni steel raw materials in the fields of aviation, aerospace and high-end civilian products. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0018] Figure 1 The present invention is a flowchart of a method for rolling an 18Ni steel master alloy ingot disclosed in some embodiments of the present invention. DETAILED DESCRIPTION
[0019] The following is a further detailed description of the embodiments of the present disclosure in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present disclosure, but cannot be used to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.
[0020] The present disclosure provides these embodiments to make the present disclosure thorough and complete, and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of the materials, the numerical expressions and the numerical values set forth in these embodiments should be interpreted as being merely exemplary, and not as limiting.
[0021] It should be noted that, in the description of the present disclosure, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0022] In addition, the words "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" does not mean vertical in the strict sense, but is within the tolerance range. "Parallel" does not mean parallel in the strict sense, but is within the tolerance range. "Include" or "comprising" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.
[0023] It should also be noted that in the description of the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.
[0024] All terms used in the present disclosure have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, for example, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined as such herein.
[0025] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.
[0026] like Figure 1 As shown, some embodiments of the present invention disclose a method for rolling an 18Ni steel master alloy ingot, which includes three steps of heating treatment, rolling and surface treatment.
[0027] Specifically, the heating treatment includes: heating the 18Ni intermediate alloy ingot to obtain an intermediate ingot; during the heating treatment, the 18Ni intermediate alloy ingot is generally heated to 1200°C~1250°C and kept warm for 2~5 hours.
[0028] The rolling process includes: rolling the intermediate ingot in a temperature range of 1050°C to 1230°C to obtain an intermediate bar; during the rolling process, the intermediate ingot needs to be rolled in multiple passes, the starting rolling temperature is not less than 1180°C; the final rolling temperature is not less than 1050°C; the rolling amount per pass is not more than 35%; and the rolling strain rate is 0.1 s -1 ~1.0 s-1 .
[0029] Finally, the intermediate bar needs to be subjected to surface treatment, that is, after the intermediate bar is cooled to room temperature, it is subjected to collision rust removal in a rust removal machine.
[0030] In the above rolling method, the composition of the 18Ni master alloy ingot may include: Ni: 18%~25%, Co: 8%~15%, Mo: 3.5%~5.0%, and the rest is Fe and unavoidable impurities. The preparation of the 18Ni master alloy ingot includes: arc furnace smelting, LF smelting, VOD furnace smelting, and casting.
[0031] Some embodiments of the present invention also disclose a 18Ni steel master alloy round bar, which is rolled by the aforementioned 18Ni steel master alloy ingot rolling method. Among them, the components and weight percentage content of the 18Ni master alloy ingot should be controlled at: Ni: 18~25%, Co: 8~15%, Mo: 3.5~5.0%, and the rest is Fe and unavoidable impurities, which is an ingot obtained by the process of "arc furnace smelting-LF (ladle refining furnace) smelting-VOD furnace smelting-pouring". The master alloy round bar has a smooth surface without cracking, and the oxygen content ranges from 0.0015% to 0.0018% in terms of mass percentage.
[0032] The rolling process mainly includes three steps: heating treatment, rolling and surface treatment. Specifically: Heating treatment: Place the 18Ni master alloy ingot into a heating furnace, heat it to 1200~1250℃, keep it warm for 2~5 hours, and then take it out of the furnace. If the temperature is too low, the rolling temperature cannot be guaranteed, which will cause cracking of the alloy during the rolling process; if the temperature is too high, it will cause energy waste or "overburning" of the alloy.
[0033] Rolling: The heated 18Ni master alloy ingot is rolled in multiple passes by a rolling mill, with the starting rolling temperature ≥1180°C, the final rolling temperature ≥1050°C, the single-pass rolling amount ≤35%, and the rolling strain rate 0.1~1.0 s-1. The inventors have found through research that the temperature range in which the 18Ni master alloy ingot has good thermoplasticity is 1050~1230°C. If the rolling temperature is too low, the alloy will crack during the rolling process; if the temperature is too high, energy will be wasted or the alloy will be "overburned". If the single-pass rolling amount is too large or the rolling strain rate is too high, the alloy will crack during the rolling process; if the rolling strain rate is too low, the rolling temperature will be low and the production efficiency will be low.
[0034] Surface treatment: After the rolled round bar is cooled to room temperature in the air, it is placed in a rust remover to remove the surface oxide scale through collision.
[0035] The rolling method of a 18Ni steel master alloy round bar and an ingot thereof disclosed in the above-mentioned embodiment of the present invention effectively solves the technical problem of rolling cracking of the 18Ni master alloy ingot by effectively controlling the rolling temperature, the single-pass rolling amount, the starting rolling temperature, the final rolling temperature and the rolling strain rate, so that the 18Ni master alloy rolled material meets the selection requirements of 18Ni steel raw materials in the fields of aviation, aerospace and high-end civilian products.
[0036] Example 1 An 18Ni master alloy ingot with the following components and weight percentage contents: Ni: 18%, Co: 15%, Mo: 3.5%, and the remainder being Fe and inevitable impurities is placed in a heating furnace, heated to 1200°C, kept warm for 5 hours, and then taken out of the furnace.
[0037] The heated 18Ni master alloy ingot is rolled in multiple passes by a rolling mill, with a starting rolling temperature of 1180 °C, a final rolling temperature of 1050 °C, a single-pass rolling amount of ≤35%, and a rolling strain rate of 0.1 s -1 .
[0038] After the rolled round bar is cooled to room temperature in the air, it is placed in a rust remover to remove the surface oxide scale through collision.
[0039] After rolling, the surface of the 18Ni master alloy bar did not crack. The oxygen content test results of the bar are shown in Table 1.
[0040] Example 2 An 18Ni master alloy ingot with the following components and weight percentage contents: Ni: 20%, Co: 11%, Mo: 4.2%, and the remainder being Fe and inevitable impurities is placed in a heating furnace, heated to 1230°C, kept warm for 2 hours, and then taken out of the furnace.
[0041] The heated 18Ni master alloy ingot was rolled in multiple passes by a rolling mill, with the starting rolling temperature of 1200 °C, the final rolling temperature of 1100 °C, the single-pass rolling amount ≤35%, and the rolling strain rate of 0.5 s -1 .
[0042] After the rolled round bar is cooled to room temperature in the air, it is placed in a rust remover to remove the surface oxide scale through collision.
[0043] After rolling, the surface of the 18Ni master alloy bar did not crack. The oxygen content test results of the bar are shown in Table 1.
[0044] Example 3 An 18Ni master alloy ingot with the following components and weight percentage contents: Ni: 25%, Co: 8%, Mo: 5.0%, and the remainder being Fe and inevitable impurities is placed in a heating furnace, heated to 1250°C, kept warm for 2 hours, and then taken out of the furnace.
[0045] The heated 18Ni master alloy ingot was rolled in multiple passes by a rolling mill, with the starting rolling temperature of 1200 °C, the final rolling temperature of 1150 °C, the single-pass rolling amount of ≤35%, and the rolling strain rate of 1.0 s -1 .
[0046] After the rolled round bar is cooled to room temperature in the air, it is placed in a rust remover to remove the surface oxide scale through collision.
[0047] After rolling, the surface of the 18Ni master alloy bar did not crack. The oxygen content test results of the bar are shown in Table 1.
[0048] Comparative Example 1 An 18Ni master alloy ingot with the following components and weight percentage contents: Ni: 20%, Co: 11%, Mo: 4.2%, and the remainder being Fe and inevitable impurities is placed in a heating furnace, heated to 1180°C, kept warm for 5 hours, and then taken out of the furnace.
[0049] The heated 18Ni master alloy ingot was rolled in multiple passes by a rolling mill, with the starting rolling temperature at 1150 °C, the final rolling temperature at 1000 °C, the single-pass rolling amount ≤35%, and the rolling strain rate at 0.5 s -1 .
[0050] After the rolled round bar is cooled to room temperature in the air, it is placed in a rust remover to remove the surface oxide scale through collision.
[0051] After the 18Ni master alloy bar was rolled using this method, obvious cracks occurred on the surface. The oxygen content test results of the bar are shown in Table 1.
[0052] Comparative Example 2 An 18Ni master alloy ingot with the following components and weight percentage contents: Ni: 20%, Co: 11%, Mo: 4.2%, and the remainder being Fe and unavoidable impurities is placed in a heating furnace, heated to 1250°C, kept warm for 2 hours, and then taken out of the furnace.
[0053] The heated 18Ni master alloy ingot was rolled in multiple passes by a rolling mill, with the starting rolling temperature of 1200 °C, the final rolling temperature of 1150 °C, the single-pass rolling amount of ≤35%, and the rolling strain rate of 2.0 s -1 .
[0054] After the rolled round bar is cooled to room temperature in the air, it is placed in a rust remover to remove the surface oxide scale through collision.
[0055] The surface of the 18Ni master alloy bar after rolling was cracked. The oxygen content test results of the bar are shown in Table 1.
[0056] Table 1 Oxygen content results of 18Ni master alloy bars after rolling
[0057] It can be seen from the above-mentioned Examples 1-3, as well as Comparative Examples 1 and 2 that the 18Ni master alloy round bars obtained in Comparative Examples 1 and 2 respectively cracked due to the temperature control and rolling strain rate not being within a reasonable range, and the oxygen content was 0.14%-0.15%, and the oxygen content of Examples 1-3 was 0.0015%-0.0018%. The oxygen content of the comparative example is much greater than that of Examples 1-3. That is to say, in the process of rolling the 18Ni master alloy ingot into round bars, the heating temperature of the heating treatment, the start rolling temperature, the final rolling temperature and the rolling strain rate all have a great influence on the cracking of the obtained round bars. At the same time, the rolling temperature needs to be controlled within the range of 1050°C to 1230°C. Only by strictly controlling various parameters within a reasonable range can the surface condition and oxygen content of the 18Ni master alloy round bars that meet the selection requirements of aviation, aerospace and high-end civilian products be obtained.
[0058] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.
[0059] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.
Claims
1. A method for rolling a 18Ni steel master alloy ingot, characterized in that: The 18Ni intermediate alloy ingot is subjected to a heating treatment to obtain an intermediate ingot; The intermediate ingot is rolled at a temperature range of 1050° C. to 1230° C. to obtain an intermediate bar; The intermediate rod is subjected to surface treatment.
2. The method for rolling a 18Ni steel master alloy ingot according to claim 1, characterized in that: The heating treatment of the 18Ni master alloy ingot includes: heating the 18Ni master alloy ingot to 1200°C-1250°C and keeping the temperature.
3. The method for rolling a 18Ni steel master alloy ingot according to claim 1, characterized in that: The step of rolling the intermediate ingot within a temperature range of 1050°C to 1230°C includes: rolling the intermediate ingot in multiple passes with a starting rolling temperature of not less than 1180°C.
4. The method for rolling a 18Ni steel master alloy ingot according to claim 3, characterized in that: The method of rolling the intermediate ingot within a temperature range of 1050°C to 1230°C also includes: the final rolling temperature is not less than 1050°C.
5. The method for rolling a 18Ni steel master alloy ingot according to claim 3 or 4, characterized in that: The intermediate ingot is rolled in a temperature range of 1050° C. to 1230° C. and the rolling amount in a single pass is not more than 35%.
6. The method for rolling a 18Ni steel master alloy ingot according to claim 3 or 4, characterized in that: The intermediate ingot is rolled in a temperature range of 1050°C to 1230°C and the rolling strain rate is 0.1 s -1 ~1.0s -1 .
7. The method for rolling a 18Ni steel master alloy ingot according to claim 1, characterized in that: The surface treatment of the intermediate bar comprises: cooling the intermediate bar to room temperature and then performing collision rust removal in a rust removal machine.
8. The method for rolling a 18Ni steel master alloy ingot according to claim 1, characterized in that: Calculated by weight percentage, the components of the 18Ni master alloy ingot include: Ni: 18%-25%, Co: 8%-15%, Mo: 3.5%-5.0%, and the rest are Fe and unavoidable impurities.
9. The method for rolling a 18Ni steel master alloy ingot according to claim 1, characterized in that: The preparation of the 18Ni master alloy ingot comprises: electric arc furnace smelting, LF smelting, VOD furnace smelting and pouring.
10. A 18Ni steel master alloy round bar, characterized in that: The 18Ni steel intermediate alloy ingot is rolled by the rolling method of any one of claims 1 to 9, and has no surface cracks. The oxygen content ranges from 0.0015% to 0.0018% in terms of mass percentage.