Shaped steel, raw materials for forming the same, shaping device and application

Abstract

The present invention provides a shaped steel, a raw material for forming the same, a shaping device and an application. The raw material for forming the shaped steel includes: C 0.60 - 0.80 wt%, Si 0.80 - 1.00 wt%, Mn 0.3 - 0.5 wt%, Ni 0.1 - 0.2 wt%, Cr 4.8 - 5.8 wt%, Mo 0.4 - 0.7 wt%, W 0.2 - 0.3 wt%, V 0.3 - 0.5 wt%, Al 0.08 - 0.15 wt%, Co 0.08 - 0.15 wt%, and the balance is Fe and inevitable impurities. By adding the above elements and limiting the content of each element at the same time, their synergistic effect can be exerted, so that the toughness, mechanical strength and heat dissipation of the obtained shaped steel can be greatly improved, and further the wear resistance and shaping dimensional accuracy of the obtained shaping device can be improved.

Description

Technical Field

[0001] The present invention relates to the field of steel manufacturing, and more particularly, to a shaped steel, a raw material for forming the same, a shaping device and an application thereof. Background Art

[0002] During the steel processing, a shaping device is usually required. The driving process of the shaping device is usually realized by the cooperation of a driven roller and a driving roller. Usually, the shaping process needs to be carried out at a relatively high temperature, and the alloy material used in the existing shaping device has poor heat dissipation, resulting in poor wear resistance; at the same time, the toughness is poor, resulting in low precision of the shaping size.

[0003] On this basis, in order to solve the above technical problems, a shaping device with good heat dissipation and high toughness is needed to improve its wear resistance and the precision of the shaping size. Summary of the Invention

[0004] The main object of the present invention is to provide a shaped steel, a raw material for forming the same, a shaping device and an application thereof, so as to solve the problems of poor heat dissipation and poor toughness of the alloy material used in the existing shaping device.

[0005] To achieve the above object, on the one hand, the present invention provides a raw material for forming a shaped steel, the raw material for forming the shaped steel comprising: C 0.60 - 0.80 wt%, Si 0.80 - 1.00 wt%, Mn 0.3 - 0.5 wt%, Ni 0.1 - 0.2 wt%, Cr 4.8 - 5.8 wt%, Mo 0.4 - 0.7 wt%, W 0.2 - 0.3 wt%, V 0.3 - 0.5 wt%, Al 0.08 - 0.15 wt%, Co 0.08 - 0.15 wt%, and the balance being Fe and inevitable impurities.

[0006] Further, the raw material for forming the shaped steel further comprises Cu 0.05 - 0.15 wt%.

[0007] Further, the raw material for forming the shaped steel further comprises N 0.012 - 0.018 wt%.

[0008] Further, the raw material for forming the shaped steel further comprises B 0.0025 - 0.0035 wt%.

[0009] On the second aspect of the present application, a shaped steel is further provided, and the shaped steel is made of the above raw material for forming the shaped steel.

[0010] On the third aspect of the present application, a shaping device is further provided, and the shaping device is made of the above shaped steel.

[0011] Further, the shaping device is selected from an active rectangular shaping roll and / or a driven rectangular shaping roll.

[0012] The fourth aspect of the present application also provides an application of a raw material for forming shaped steel in the field of steel manufacturing.

[0013] By applying the technical solution of the present invention, by adding the above elements and limiting the content of each element at the same time, their synergistic effect can be exerted, so that the toughness, mechanical strength and heat dissipation of the shaped steel prepared therefrom can be greatly improved, and further the wear resistance and shaping dimensional accuracy of the shaping device prepared therefrom can be improved. Detailed Embodiments

[0014] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0015] As described in the background art, the alloy materials used in the existing shaping devices have problems of poor heat dissipation and poor toughness. To solve the above technical problems, the present application provides a raw material for forming shaped steel, and the raw material for forming shaped steel includes: C 0.60 - 0.80 wt%, Si 0.80 - 1.00 wt%, Mn 0.3 - 0.5 wt%, Ni 0.1 - 0.2 wt%, Cr 4.8 - 5.8 wt%, Mo 0.4 - 0.7 wt%, W 0.2 - 0.3 wt%, V 0.3 - 0.5 wt%, Al 0.08 - 0.15 wt%, Co 0.08 - 0.15 wt%, and the balance is Fe and inevitable impurities.

[0016] Element C can improve the strength of shaped steel through interstitial solid solution. However, excessive C is not conducive to the welding of shaped steel. Therefore, on the premise of ensuring strength, the content of C should be reduced as much as possible. Element Si is a good deoxidizer. An appropriate amount of Si can significantly improve the deoxidation ability of Al and also inhibit the nucleation of δ-ferrite. However, excessive Si will coarsen austenite, increase the temper brittleness of shaped steel, and reduce the plasticity of shaped steel. Element Mn can not only improve the hardenability and hot workability of shaped steel, but also enable products with larger cross-sections to obtain uniformly refined structures, thereby reducing the performance differences in different parts. Moreover, it expands the austenite phase region and stabilizes the austenite structure, improving the strength of the material without reducing its toughness. Element Ni is the main element for forming and stabilizing austenite. It can lower the critical transformation temperature and reduce the diffusion rate of each element in shaped steel, thus improving the hardenability of shaped steel and enhancing its low-temperature toughness. However, Ni is a scarce strategic resource with a relatively high price. Therefore, on the premise of fully exerting the effect of Ni element, the content of Ni element should be reduced as much as possible. Element Cr can significantly increase the hardenability of shaped steel, improve its antioxidant effect, and enhance its corrosion resistance. When used in combination with C element and Mo element, it can refine grains, enhance the toughness and wear resistance of shaped steel. However, excessive Cr will increase the tendency of temper brittleness of shaped steel, resulting in poor strength and toughness of shaped steel. Element Mo can improve the hardenability of shaped steel. When coexisting with Cr element, Mn element, etc., it can inhibit the temper brittleness caused by other elements, improve the corrosion resistance in the medium, and prevent pitting corrosion tendency. However, when the content of Mo element exceeds 0.8wt%, the effect is not obvious, and it will lead to poor welding performance of shaped steel. Element W mainly increases the temper stability of shaped steel and improves its strength. When the special compounds formed by W element and C element are dispersed in shaped steel, they can significantly refine grains, improve the strength and toughness of shaped steel, and enhance the temper stability of martensite after quenching. In this way, a higher temperature and longer holding time are required during the tempering process, which is beneficial to eliminating the internal stress of quenching, making shaped steel have higher toughness and environmental corrosion resistance. Element V mainly refines grains in shaped steel, increases the strength and toughness of shaped steel, and inhibits its aging effect. However, the content of V element should not be too high. When V exceeds 0.1wt%, it will have an adverse effect on the toughness of shaped steel. Element Al is a good deoxidizer and grain-refining element in shaped steel. It inhibits the aging of shaped steel, improves the toughness of shaped steel at low temperatures, and enhances its antioxidant performance. However, when the content of Al is too high, it will lead to an increase in non-metallic inclusions in shaped steel, resulting in poor toughness. The addition of Co element is mainly used to improve the strength and heat resistance of shaped steel. By adding the above elements and limiting the content of each element, their synergistic effect can be exerted, thereby significantly improving the toughness, mechanical strength, and heat dissipation of the obtained shaped steel.

[0017] In a preferred embodiment, the raw materials for forming shaped steel also include 0.05 - 0.15 wt% of Cu. The Cu element is an austenite-forming element in steel, with a low solubility in ferrite. As the temperature drops, the solubility decreases rapidly, and at room temperature, Cu is almost insoluble in α-Fe. Therefore, after treatment, the Cu element will precipitate in the form of a second phase, thereby strengthening the steel. The addition of Cu can not only promote the formation of a protective film on the steel surface, reducing the entry of H atoms into the steel matrix, but also the nano-sized Cu-rich phase precipitated during aging can trap hydrogen and act as a beneficial hydrogen trap. These two effects of Cu in steel can significantly reduce the harmful effects of H on the steel. Cu in steel also has corrosion resistance to microorganisms. When the Cu content is low, the Cu-rich phase precipitated in the matrix is insufficient, and the corrosion resistance to microorganisms is small; when the Cu content is relatively too high, it will have an adverse impact on the impact toughness and hot working performance. The dosage of the copper element includes but is not limited to the above range, and limiting it within the above range can further improve the mechanical strength and biocorrosion resistance of the shaped steel prepared therefrom.

[0018] In a preferred embodiment, the raw materials for forming shaped steel also include 0.012 - 0.018 wt% of N. The dosage of the nitrogen element includes but is not limited to the above range, and limiting it within the above range is beneficial to further refine the grains, thereby further improving the toughness and wear resistance of the steel.

[0019] In a preferred embodiment, the raw materials for forming shaped steel also include 0.0025 - 0.0035 wt% of B. The dosage of the boron element includes but is not limited to the above range, and limiting it within the above range is beneficial to further improve the forging performance of the shaped steel, thereby improving the workability.

[0020] The second aspect of the present application provides a shaped steel, which is prepared using the above-mentioned composition for forming shaped steel provided by the present application.

[0021] By simultaneously adding elements such as C, Si, Mn, Ni, Cr, Mo, W, V, Al, Co, etc. to iron element and limiting the dosage of each element, through the synergistic effect of the above elements, the toughness, mechanical strength and heat dissipation of the shaped steel prepared therefrom are significantly improved.

[0022] It should be noted that the preparation process of the shaped steel is relatively mature, and the shaped steel provided by the present application is produced using a conventional process even.

[0023] The third aspect of the present application also provides a sizing device, which is made of the sizing steel provided by the present application. Since the above-mentioned sizing steel has high toughness, mechanical strength and heat dissipation, the sizing device made of the above-mentioned sizing steel has excellent wear resistance and high dimensional accuracy. Preferably, the above-mentioned sizing device includes, but is not limited to, an active sizing rectangular roller and / or a driven sizing rectangular roller.

[0024] The fourth aspect of the present application provides an application of the above raw materials for forming sizing steel in the field of steel manufacturing.

[0025] Since the sizing steel made of the above composition has high toughness, mechanical strength and heat dissipation, it greatly broadens the application scenarios of steel.

[0026] The following further describes the present application in detail with specific embodiments, and these embodiments should not be construed as limiting the scope claimed by the present application.

[0027] The main components in the raw materials for forming sizing steel are shown in Table 1, and the rest is made up to 100 wt% with iron and impurities.

[0028] The sizing steel in each example and comparative example is prepared by the following method:

[0029] (1) Select high-quality scrap steel and low-phosphorus and low-sulfur hot metal as the raw materials for electric furnace smelting, and ensure that the C content in the molten steel tapped from the electric furnace is ≥ 0.10%, the P content is ≤ 0.02%, and the tapping temperature is ≥ 1600 °C.

[0030] (2) During the refining process, charge according to the process requirements, do not add scrap steel, only add appropriate proportions of alloys, desulfurize with calcium aluminate in the refining furnace, and fine-tune the composition to ensure that the LF refining (ladle refining) time is ≥ 40 min, the VD (vacuum degassing refining) holding time is ≥ 10 min, and the soft blowing argon time is ≥ 12 min. After vacuum treatment, the molten steel composition meets the material design requirements: C 0.60 - 0.80 wt%, Si 0.80 - 1.00 wt%, Mn 0.3 - 0.5 wt%, Ni 0.1 - 0.2 wt%, Cr 4.8 - 5.8 wt%, Mo 0.4 - 0.7 wt%, W 0.2 - 0.3 wt%, V 0.3 - 0.5 wt%, Al 0.08 - 0.15 wt%, Co 0.08 - 0.15 wt%, and the balance is Fe and unavoidable impurities. The gas content is controlled: [O] ≤ 20 PPm, [H] ≤ 2 PPm.

[0031] (3) Protect the casting with argon to avoid secondary pollution control of the molten steel.

[0032] (4) Electro-slag remelting is carried out under argon gas protection to reduce large particle inclusions, disperse small particle inclusions, eliminate or mitigate defects such as porosity, and obtain an ingot with uniform composition and dense structure.

[0033] (5) The ingot is processed by extrusion forging at 900 - 1000 °C to make a finished blank with rough machining allowance. Inspect the material surface, and if cracks are found, they need to be removed to obtain a high-quality ingot with uniform, refined grains and denser structure.

[0034] (6) The blank is subjected to spheroidizing annealing treatment. The annealing temperature is slightly higher than Ac1, and it is held for 6 - 10 hours to improve the machining performance.

[0035] (7) The blank is rough-turned to make a finished blank with finish machining allowance.

[0036] (8) High-temperature quenching is carried out by heating to Ac1 + 150 °C, and then tempering is carried out at 400 - 450 °C.

[0037] (9) Finish machining to the finished product size.

[0038] (10) After testing, the chemical composition, mechanical properties, structure, metallurgical quality, dimensional tolerance distribution, surface condition, etc. of the finished product meet the requirements.

[0039] (11) It is fixed and packaged in wooden cases and shipped out of the factory.

[0040] Table 1

[0041]

[0042]

[0043] Performance testing:

[0044] Mechanical strength: The test method can be found in the national standard number GB / T 228. Toughness: The test method can be found in the national standard number GB / T 229.

[0045] Heat dissipation performance: The test method can be found in the national standard number GB / T 3651 - 2008 Measurement method for thermal conductivity of metals at high temperature.

[0046] Sizing accuracy: The test method can be found in the national standard number GB / T1503 - 2008.

[0047] Bio-corrosion resistance: The test method can be found in the national standard number JB / T 7901 - 2001 Laboratory immersion test method for uniform corrosion of metallic materials.

[0048] Table 2

[0049]

[0050] Sizing accuracy: The product surface is smooth; the dimensions meet the requirements of the drawings.

[0051] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: By adding the above elements and limiting the content of each element at the same time, their synergistic effect can be exerted, so that the toughness, mechanical strength and heat dissipation of the sized steel produced can be greatly improved.

[0052] It should be noted that the terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those described herein.

[0053] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A raw material for forming shaped steel, characterized in that, The raw materials for forming the shaped steel include: C 0.60 - 0.80 wt%, Si 0.80 - 1.00 wt%, Mn 0.3 - 0.5 wt%, Ni 0.1 - 0.2 wt%, Cr 4.8 - 5.8 wt%, Mo 0.4 - 0.7 wt%, W 0.2 - 0.3 wt%, V 0.3 - 0.5 wt%, Al 0.08 - 0.15 wt%, Co 0.08 - 0.15 wt%, Cu 0.05 - 0.15 wt%, N 0.012 - 0.018 wt%, B 0.0025 - 0.0035 wt%, and the balance is Fe and inevitable impurities.

2. A shaped steel, characterized in that, The shaped steel is prepared from the raw materials for forming the shaped steel as described in claim 1.

3. A shaping device, characterized in that, The shaping device is prepared from the shaped steel as described in claim 2.

4. The shaping device according to claim 3, wherein The shaping device is selected from an active rectangular roller and / or a driven rectangular roller.

5. Application of the raw materials for forming the shaped steel as described in claim 1 in the field of steel manufacturing.

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