Highly wear resistant stone cutting saw blade substrate steel and method of making

Abstract

The application discloses a high-wear-resistance stone cutting saw blade base steel and a manufacturing method thereof, and chemical components are as follows: C 0.75-0.85%, Si 0.5-1.0%, Mn 0.3-1.1%, P <=0.02%, S <=0.01%, Al 0.02-0.06%, Cr 1.0-1.5%, Mo 0.2-0.5%, V 0.05-0.2%, B 0.0005-0.002%, W 0.5-1.0%, and the rest is Fe and inevitable impurities. The manufacturing method comprises smelting, heavy pressing, rolling, on-line cooling and normalizing heat treatment processes. The steel plate has a tensile strength of 1450-1650 MPa, an elongation of 6-8%, a hardness of 50-58 HRC and a hardness retention rate at 300 DEG C of greater than or equal to 90%. The high-wear-resistance stone cutting saw blade base steel and the production process thereof have mechanical properties and high-wear-resistance safety performance which can meet service conditions in the stone cutting field.

Description

Technical Field

[0001] This invention belongs to the field of steel material preparation, and in particular to a base steel for a high wear-resistant stone cutting saw blade and its manufacturing method. Background Technology

[0002] As the most critical cutting tool in stone processing, the overall performance of a saw blade depends not only on the hardness and sharpness of its teeth but also, and more importantly, on the comprehensive performance of its base steel plate. Saw blades operate under high-speed rotation, cyclic impact loads, and complex frictional heat environments, placing extremely stringent demands on the strength, toughness, elasticity, wear resistance, and dimensional stability of the base steel plate. With continuously increasing cutting speeds, diversifying processed materials, and enhancing equipment automation, the performance provided by traditional general-purpose medium carbon steels (such as 65Mn and 75Cr1) is no longer sufficient to meet the development needs of the modern saw blade industry. Therefore, the development of specialized steel plates for saw blade bases has become a key technological direction for the industry.

[0003] The existing saw blade base steel plates suffer from the following technical shortcomings: First, traditional steel grades have limited hardenability, often resulting in inconsistent microstructures in thick plates, with a surface layer of martensite and a core of bainite or ferrite. This leads to severe deformation and high internal stress after quenching, affecting cutting stability and service life. Second, the saw blade base is subjected to severe temperature gradients and phase transformation expansion during quenching, making it highly susceptible to defects such as warping, wavy deformation, or twisting. Traditional processes rely heavily on experience to adjust cooling methods and straightening procedures, making it difficult to achieve high repeatability and batch stability. Furthermore, as the saw blade industry develops towards high speed, high load, and high precision, the base steel plate also needs to possess high resistance to temper softening. In stone cutting operations, the local temperature of the saw blade can reach 300~600℃ during operation. Ordinary medium carbon steel is prone to significant softening in this temperature range, leading to decreased strength, increased deformation, and even safety hazards such as tooth root cracking and saw blade deviation. On the other hand, welding of saw teeth has become widely used in saw blade manufacturing in recent years. However, due to the local heating temperature reaching 900-1100℃ during the welding process, if the thermal shock resistance and structural stability of the base steel are insufficient, a heat-affected zone (HAZ) with brittleness or stress concentration can easily form in the tooth root region, leading to failure modes such as tooth peeling and crack initiation. Traditional materials, due to their low alloy content, poor structural stability, and limited high-temperature resistance, struggle to maintain good overall performance in both welded teeth and actual cutting environments. Traditional saw blade steel plates generally exhibit low wear resistance, fatigue resistance, and crack propagation resistance, making them unsuitable for high-speed machining and high-frequency vibration conditions. With the development of automated machining equipment, the stability requirements for saw blades have further increased, and simply relying on performance improvements in the hard materials of the teeth is no longer sufficient to meet overall durability requirements. The strength, toughness, and residual stress control of the base steel plate have become key factors determining saw blade life and machining accuracy.

[0004] The patent with publication number 201510965259.4, entitled "A Boron-Containing High-Carbon Saw Blade Steel and Its Manufacturing Method", proposes a high-hardness saw blade steel plate. It adopts a composition design with high C, Si, Mn and B elements. The steel plate produced by this composition and process only considers high hardness and does not combine alloying elements such as Ni, Cr, and W. While ensuring the hardness and wear resistance of the steel plate, it also ensures the tooth root anti-splitting performance.

[0005] The patent with publication number 202010479038.7, entitled "Steel for Carbide Toothed Circular Saw Blade and its Heat Treatment Method", proposes a carbide saw blade steel. This invention adopts a medium-C high-Mn combined Cr, Ni and Mo alloy system, combined with conventional heat treatment process. Since there are no other alloy components, it is impossible to produce high hardness and high wear resistance saw blade steel plates.

[0006] The patent with publication number 202210914297.7, entitled "A Steel for Ultra-High Hardness Saw Blades and Its Manufacturing Method", proposes an ultra-high hardness saw blade steel. This invention only requires the Rockwell hardness and room temperature impact toughness of the steel plate. It adds elements such as Ni, Cu, and rare earth elements to the steel, which increases the cost and cannot improve the wear resistance and tooth root anti-fracture performance. Moreover, it only uses conventional steelmaking, rolling and offline heat treatment processes. This composition and process cannot produce steel plates with a thickness of 10-16 mm and excellent wear resistance. This patent is significantly different from the present invention.

[0007] Existing steel plates for saw blades have significant shortcomings in terms of high wear resistance, saw tooth chipping resistance, and flatness control. To meet the demands of modern high-performance saw blades, there is an urgent need to develop a specialized steel plate material with a rationally designed composition, stable heat treatment process, high wear resistance, long fatigue life, and applicability to saw blades of varying thicknesses, along with a matching advanced manufacturing method. This invention focuses on innovative design to address these key issues, aiming to significantly improve the overall performance, safety, and service life of the saw blade base steel plate. Summary of the Invention

[0008] The purpose of this invention is to prepare a high wear-resistant saw blade base steel plate suitable for stone cutting. Addressing the compositional and performance requirements of high wear-resistant saw blade steel in the stone cutting environment, this invention utilizes a combination of elements such as C, Si, Mn, Cr, Mo, and W, along with microalloying elements like V and B, in a specific compositional design and key production technology for high wear-resistant stone cutting saw blade base steel. The invention relates to a high wear-resistant stone cutting saw blade base steel and its manufacturing method, whose mechanical properties and high wear resistance safety performance meet the service requirements in the stone cutting field. To achieve the objectives of this invention, the inventors conducted extensive and systematic experimental research in several aspects, including alloy element screening and proportioning, steel cleanliness control, efficient rolling, and optimization and parameter selection of the normalizing process. Ultimately, the alloy element proportions and production process that meet the objectives of this invention were determined.

[0009] One of the technical solutions of this invention is to propose a high wear-resistant stone cutting saw blade base steel. The specific technical solution is as follows: the chemical composition by mass percentage is: C: 0.75~0.85%, Si: 0.5~1.0%, Mn: 0.3~1.1%, P≤0.02%, S≤0.01%, Als: 0.02~0.06%, Cr: 1.0~1.5%, Mo: 0.2~0.5%, V: 0.05~0.2%, B: 0.0005~0.002%, W: 0.5~1.0%, with the remainder being Fe and unavoidable impurities.

[0010] The reasons for selecting the above alloying elements and their contents in this invention are as follows: C: As a basic strengthening element in steel, C can improve the hardenability of the steel plate during quenching, thereby enhancing its hardness and wear resistance. Excessive C content will produce a large amount of hardened structure, reducing the tendency of the steel plate to develop tooth root cracks. Therefore, the C content in this invention is 0.75~0.85%.

[0011] Si: Si plays a solid solution strengthening role in steel; adding a certain amount of Si to steel can inhibit crystal growth and improve the hardness, strength, wear resistance and tempering stability of steel plates. However, adding Si will reduce the toughness of steel plates, so its content needs to be precisely controlled. The Si content in this invention is 0.5~1.0%.

[0012] Mn: Mn can dissolve in large quantities in the Fe matrix along with Ni and Cu, increasing hardenability and improving the strength and toughness of the steel plate. When the Mn content is below 0.3%, its contribution to the strength of the steel plate is relatively small. The Mn content can be appropriately increased. In this invention, the Mn content is 0.3% to 1.1%.

[0013] P and S: P and S elements have no benefit to the mechanical properties of steel plates, especially elongation. Therefore, the content of P should be controlled to ≤0.02% and S ≤0.01%.

[0014] Als: Al is the main deoxidizing element in steel. Excessive Al content will form large inclusions, affecting the wear resistance of steel plates. The Al content should be reduced as much as possible. In this invention, the Al content is controlled at 0.02~0.06%.

[0015] Cr: Cr can effectively improve the strength of steel plates. Appropriately increasing the Cr content can form Cr7C3, which significantly improves wear resistance. At the same time, Cr can also improve hardenability and inhibit cracking. However, excessive Cr content will deteriorate the toughness of steel plates, so it needs to be precisely controlled within the range of 1.0~1.5%.

[0016] Mo: Mo can significantly improve the strength and hardness of steel plates, and this strengthening effect is particularly pronounced at high temperatures, enabling the steel plates to achieve higher yield strength and tensile strength. Adding an appropriate amount of Mo to heat-treated steel plates can improve their resistance to pitting corrosion cracking; simultaneously, the formed Mo2C can improve high-temperature hardness retention and resistance to tempering softening; furthermore, the combination of Mo with elements such as Cr is a targeted design feature of this invention for achieving specific effects. Therefore, the Mo content in this invention is 0.2~0.5%.

[0017] V: V, through its interaction with elements such as C and N in steel, refines the grain size, thereby improving the strength, toughness, and resistance to chipping of the steel plate. During the heat treatment of quenched and tempered steel plates, V effectively improves the high-temperature thermal stability of the steel plate, controls abnormal austenite grain growth, and enhances hardenability. Therefore, the V content in this invention is 0.05~0.2%.

[0018] B: B can segregate at austenite grain boundaries, inhibiting ferrite nucleation from grain boundaries and delaying phase transformation; it does not directly increase hardness, but it can significantly improve the depth and hardenability of the hardened layer, enabling thick plates to achieve full-section martensitic transformation. Therefore, the B content in this invention is 0.0005~0.002%.

[0019] W significantly enhances strength and can form dispersed W-based carbides with Fe, Cr, and Mo, creating a W2C / WC structure that maintains wear resistance at high temperatures. W also improves the thermal stability of the steel plate, and the fine hard phases formed during normalizing further enhance wear resistance and high-temperature hardness. Therefore, the W content in this invention is 0.5~1.0%.

[0020] Preferably, the microstructure of the steel plate includes martensite and bainite, and contains a large amount of M7C3 and M. 23 C6 carbides, wherein the martensite content is 70-80% and the bainite content is 20-30%, wherein M7C3, M 23 C6 carbides have a size of 50–150 nm and a dislocation density ≥1.e+10 cm. -2 The proportion of large-angle grain boundaries is ≥40%, and the effective grain size is 4~8 μm.

[0021] Preferably, the steel plate has a tensile strength of 1450~1650 MPa, an elongation of 6~8%, a hardness of 50~58 HRC, a hardness retention rate of ≥90% at 300 ℃, and a finished steel plate thickness of 10~16 mm.

[0022] Preferably, compared with traditional 65Mn, 75Cr1 and ordinary 9CrSi saw blade steel, the steel plate of the present invention has 50-80% improved wear resistance, improved tooth root anti-splitting performance, and reduced tooth breakage probability by 4-7%.

[0023] The second technical solution of this invention is to propose a method for manufacturing high corrosion-resistant stainless steel saw blade steel, including smelting, heavy pressing, rolling and online cooling, and normalizing heat treatment processes, characterized in that: Rolling and Online Cooling Process: The continuously cast billet adopts a direct-loading process, charging it into the heating furnace at 400-700℃ and holding it for 1-2 hours. This aims to maintain a uniform temperature throughout the thickness of the billet during the low-temperature stage, addressing the cracking problem caused by uneven temperature in high-W, high-Mn continuously cast billets during heating. During subsequent heating, the heating rate is controlled at 1-4℃ / min to avoid large temperature gradients within the billet, which can generate internal stress. The heating temperature is 1160-1260℃, held for 3-5 hours. This high-temperature homogenization and holding period ensures complete dissolution of C / N compounds and uniform heating throughout the thickness of the steel plate, allowing it to soften sufficiently.

[0024] The initial rolling temperature is 1140~1240 ℃, the average reduction per pass is 5%~10%, and the final rolling temperature is 760~900 ℃. After rolling, online water cooling is used for cooling, with a water cooling rate of 8~12 ℃ / s. The high-temperature, low-reduction rolling process is formulated in conjunction with the unique alloy composition design of the steel plate of this invention. Due to the addition of a large amount of hardening elements such as W, Mn, Cr, and Mo to the steel, the steel plate has high hardness and stiffness at lower rolling temperatures, resulting in greater rolling force. Rolling can only be carried out at high temperatures. Furthermore, the hard and brittle phases are prone to bending deformation of the steel plate during high-reduction rolling. Therefore, the deformation of the steel plate should be controlled at a lower reduction rate. This is the unique design of the steel plate production process of this invention.

[0025] Normalizing heat treatment process: Normalizing temperature is 760~860 ℃, and normalizing holding time is 2.0~3.0 min / mm; stress-relieving tempering temperature is 150~300 ℃, and stress-relieving tempering holding time is 2.0~3.0 min / mm. Normalizing is used to eliminate the inhomogeneity, banded structure and coarse grains formed during rolling and online cooling. Through complete austenitization followed by air cooling, the steel obtains fine and uniform martensite + bainite and a large amount of M7C3 and M... 23 C6 carbides provide a consistent and controllable initial microstructure for subsequent stress-relieving tempering, thereby improving the uniformity of hardness distribution and the stability of toughness. Stress-relieving tempering, performed after straightening, aims not to reduce hardness, but to release the phase transformation stress, thermal stress, and residual stress introduced by the previous heat treatment and mechanical straightening. It stabilizes the flatness and internal tension of the saw blade, preventing warping, misalignment, or premature cracking during cutting or high-speed rotation. These two processes work together to ensure that the saw blade steel possesses both a good microstructure and maintains long-term stability in dimensional and wear resistance during service.

[0026] Furthermore, during the smelting process, the molten steel is refined through a converter, LF furnace, RH or VD furnace to further reduce the content of P, S and non-metallic inclusions.

[0027] Furthermore, during the casting process, at the front end of the core solidification zone, a compression roller is used to apply heavy pressure, with a total reduction of ≥10 mm. The secondary cooling water flow is controlled to ensure that the surface cooling rate of the continuously cast billet is 0.2~0.6 ℃ / s, the center cooling rate is 0.05~0.2 ℃ / s, and the billet pulling speed is 0.8~1.2 m / min. The purpose of using heavy pressure in the continuous casting process is to forcibly eliminate the center segregation and porosity defects caused by solidification shrinkage at the last moment of steel solidification, compress the dendrite spacing in the core solidification pasty zone, inhibit solute enrichment in the central region, improve the uniformity of the central composition, and, combined with the billet pulling speed and cooling rate, provide a high-quality core foundation for subsequent rolling and heat treatment.

[0028] Using the aforementioned chemical composition and process, a high-wear-resistant saw blade base steel plate suitable for stone cutting is prepared. Its mechanical properties and high wear resistance safety performance meet the service requirements for stone cutting. The finished high-wear-resistant stone cutting saw blade base steel has a thickness of 10-16 mm, a tensile strength of 1450-1650 MPa, an elongation of 6-8%, a hardness of 50-58 HRC, improved wear resistance by 50-80%, improved tooth root anti-chipping performance, reduced tooth chipping probability by 4-7%, and a hardness retention rate of ≥90% at 300 ℃. This establishes a specific set of high-wear-resistant stone cutting saw blade base steel composition and corresponding production processes.

[0029] Compared with the prior art, the present invention has the following advantages: 1. The innovative alloy composition system of this invention can guarantee a tensile strength of 1450~1650 MPa, an elongation of 6~8%, a hardness of 50~58 HRC, and a finished thickness of 10~16 mm for the base steel plate of the high wear-resistant stone cutting saw blade.

[0030] 2. This invention utilizes Cr, Mo, W, and V to form a composite carbide reinforcement structure, causing high-hardness, wear-resistant phases such as M7C3, Mo2C, and VC to disperse and precipitate within the martensitic-bainitic matrix of the steel plate, effectively suppressing abrasive cutting and surface ploughing wear. Compared with traditional 65Mn, 75Cr1, and ordinary 9CrSi saw blade steel, under the same stone cutting conditions, the wear resistance is improved by 50-80%, and the probability of tooth breakage is reduced by 4-7%. This beneficial effect significantly extends the service life of stone saw blades in environments with strong abrasive wear, reducing replacement frequency and operating costs.

[0031] 3. This invention employs a multiphase microstructure design of "martensite + 20~30% bainite," enabling the steel plate to maintain high hardness while possessing excellent energy absorption capacity and crack propagation resistance. Simultaneously, by refining grains and pinning crack initiation sites through nano-carbides such as VC and Mo2C, the risk of brittle failure under impact loads is significantly reduced. Comparative tests show improved tooth root anti-scraping performance, a 4~7% reduction in tooth breakage probability, and a hardness retention rate of ≥90% at 300 ℃. Attached Figure Description

[0032] Figure 1 The metallographic structure of the steel plate in Example 1 is martensite + bainite, containing a large amount of M7C3 and M. 23 C6 carbides, wherein the martensite content is 73% and the bainite content is 27%, wherein M7C3 and M 23 The C6 carbide has a size of 63.5 nm and a dislocation density of 1.64e+10 cm. -2 It has a large-angle grain boundary ratio of 61.51%, an effective grain size of 5.66 μm, and good mechanical properties. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of exemplary embodiments of the experimental method is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] This invention is achieved through the following process steps: Molten steel is refined in a converter, LF furnace, RH furnace, or VD furnace; during the casting process, a compression roller is used to apply heavy pressure 2-3 m from the front end of the core solidification zone, with a total reduction ≥10 mm; the secondary cooling water volume is controlled to maintain a surface cooling rate of 0.2-0.6 ℃ / s, a center cooling rate of 0.05-0.2 ℃ / s, and a billet pulling speed of 0.8-1.2 m / min; the continuous casting billet is directly loaded into the heating furnace at a furnace temperature of 400-700 ℃ and held for 1-2 h; during subsequent heating, the heating rate is controlled at 1-4 ℃ / min, and the heating temperature is 1160-1260 ℃ for 3-5 h; the initial rolling temperature is 1140-1240 ℃, the average reduction per pass is 5%-10%, and the final rolling temperature is 760-900 ℃. The rolling process is carried out using online water cooling at a rate of 8-12 ℃ / s; the normalizing temperature is 760-860 ℃, and the normalizing holding time is 2.0-3.0 min / mm; the stress-relieving tempering temperature is 150-300 ℃, and the stress-relieving tempering holding time is 2.0-3.0 min / mm; the finished steel plate thickness is 10-16 mm.

[0035] The following embodiments are merely some preferred embodiments of the present invention and do not limit the scope and technical means of the invention in any way. Table 1 shows the chemical composition of Examples 1-20, Table 2 shows the process parameters of the steel under heavy pressure in each embodiment, Table 3 shows the process parameters of rolling and online cooling of the steel in each embodiment, Table 4 shows the process parameters of normalizing heat treatment of the steel in each embodiment, and Table 5 shows the microstructure and mechanical properties of the steel plates in each embodiment of the present invention.

[0036] Table 1 Chemical composition (wt, %) of the steel in the examples 1 0.832 0.987 1.058 0.019 0.001 0.059 1.22 0.24 0.161 0.0014 0.63 2 0.756 0.718 0.833 0.009 0.006 0.021 1.31 0.39 0.079 0.001 0.87 3 0.766 0.509 0.459 0.019 0.007 0.025 1.49 0.25 0.134 0.0006 0.78 4 0.824 0.779 1.049 0.001 0.009 0.039 1.35 0.39 0.191 0.0017 0.62 5 0.826 0.602 0.314 0.011 0.001 0.052 1.08 0.32 0.158 0.0012 0.82 6 0.835 0.738 0.901 0.004 0.008 0.032 1.07 0.33 0.062 0.001 0.87 7 0.777 0.957 0.595 0.004 0.001 0.046 1.10 0.26 0.058 0.0014 0.80 8 0.792 0.615 0.551 0.009 0.002 0.045 1.01 0.49 0.092 0.0006 0.81 9 0.821 0.825 1.056 0.002 0.001 0.049 1.11 0.44 0.131 0.0006 0.67 10 0.765 0.631 0.909 0.001 0.002 0.050 1.14 0.31 0.121 0.0019 0.95 11 0.784 0.667 0.936 0.01 0.007 0.025 1.28 0.47 0.145 0.002 0.90 12 0.817 0.521 0.756 0.002 0.002 0.043 1.02 0.25 0.078 0.0011 0.81 13 0.843 0.634 0.529 0.015 0.008 0.045 1.31 0.24 0.195 0.0005 0.55 14 0.837 0.644 0.673 0.018 0.007 0.052 1.41 0.25 0.187 0.001 0.67 15 0.783 0.577 0.333 0.007 0.002 0.032 1.47 0.32 0.155 0.0009 0.52 16 0.815 0.714 1.088 0.003 0.006 0.029 1.37 0.21 0.094 0.0016 0.95 17 0.796 0.667 0.874 0.008 0.009 0.049 1.14 0.27 0.199 0.0006 0.92 18 0.793 0.979 1.024 0.013 0.004 0.020 1.16 0.34 0.108 0.0014 0.93 19 0.839 0.647 0.627 0.012 0.007 0.058 1.28 0.46 0.089 0.0018 0.64 20 0.823 0.924 0.999 0.013 0.003 0.033 1.08 0.39 0.123 0.0007 0.65 Table 2 Process parameters under heavy steel pressure in each embodiment 1 15.3 0.27 0.09 0.83 2 14.8 0.55 0.10 0.81 3 12.0 0.43 0.19 0.85 4 16.1 0.40 0.19 0.85 5 10.7 0.37 0.17 0.95 6 11.0 0.39 0.17 0.99 7 17.4 0.50 0.10 1.09 8 17.2 0.48 0.06 1.09 9 10.4 0.35 0.07 1.14 10 11.3 0.47 0.08 0.99 11 13.6 0.37 0.11 0.83 12 15.7 0.53 0.10 1.11 13 13.2 0.35 0.08 1.08 14 13.7 0.29 0.15 0.95 15 14.6 0.28 0.13 1.14 16 12.8 0.48 0.18 1.12 17 10.4 0.60 0.07 1.17 18 11.2 0.37 0.12 0.82 19 10.8 0.52 0.16 1.12 20 16.7 0.36 0.19 0.85 Table 3. Process parameters for steel rolling and online cooling in each embodiment. 1 500 1.0 3.7 1168 4.6 1153 7.2 869 9.6 2 511 2.0 2.0 1244 4.9 1240 5.3 762 10.9 3 449 1.5 3.7 1172 3.8 1160 6.5 877 11.2 4 509 1.8 1.8 1237 3.4 1144 8.5 821 11.6 5 498 1.1 3.0 1243 3.3 1186 8.0 873 8.7 6 679 1.5 2.8 1178 5.0 1142 8.8 761 10.8 7 547 1.1 1.9 1203 3.5 1201 8.4 888 10.2 8 594 1.7 2.8 1183 5.0 1174 8.5 818 11.8 9 519 1.9 2.4 1218 4.3 1172 9.3 866 8.2 10 694 2.0 2.6 1186 4.6 1181 5.4 789 9.7 11 645 1.3 1.8 1218 3.3 1195 8.4 879 11.6 12 666 1.7 2.2 1222 3.5 1154 5.2 900 9.2 13 519 1.4 1.2 1214 4.4 1197 5.1 858 8.6 14 583 1.6 1.5 1175 4.5 1150 6.7 778 11.3 15 603 1.7 1.2 1256 4.1 1149 8.7 844 8.6 16 617 1.5 2.0 1233 4.6 1172 6.3 880 9.2 17 670 1.6 3.0 1244 4.0 1214 8.4 776 8.3 18 512 1.1 3.8 1207 3.1 1197 5.5 840 10.5 19 692 1.4 3.7 1224 3.8 1212 6.7 873 9.0 20 488 1.1 1.9 1196 4.9 1141 5.2 786 9.4 Table 4 Process parameters for normalizing heat treatment of steel in each embodiment 1 815 3.0 191 2.2 2 819 2.8 197 2.1 3 804 2.1 257 2.7 4 810 2.2 177 2.6 5 842 2.2 245 2.6 6 792 2.8 159 2.8 7 801 2.5 198 2.1 8 825 2.1 248 2.6 9 794 2.9 155 2.6 10 816 2.2 203 2.1 11 787 2.7 261 2.4 12 763 2.3 196 2.4 13 849 2.9 289 2.4 14 764 2.2 277 2.6 15 856 2.4 198 2.8 16 793 2.5 195 2.8 17 830 2.2 237 2.9 18 840 2.5 172 2.0 19 824 2.1 176 2.1 20 847 2.3 299 2.1 Table 5. Microstructure and mechanical properties of steel plates in various embodiments of the present invention 1 15 73 27 63.5 1.64 61.51 5.66 1451 8 56.2 69.1 6.8 94.1 2 14.6 77 23 121.3 1.91 52.2 7.9 1460 6 52.13 73.7 6.6 94.9 3 12.2 77 23 91.2 1.13 57.37 5.59 1630 7 50.15 59.2 6.5 91.7 4 12.8 77 23 76.5 1.32 53.98 6.93 1577 8 56 79 6.7 95 5 15.2 73 27 106.9 3.49 57.96 7.34 1559 8 56.18 63.9 5.4 95 6 14.4 79 21 53.8 2.8 47.2 4.64 1553 7 52.79 51.4 4.9 90.1 7 14.8 72 28 67.7 1.74 53.04 6.24 1515 6 57.95 51.2 4.7 93 8 15.6 77 23 53.8 1.75 46.95 6.87 1534 8 53.25 76.6 6.3 95.4 9 11.9 73 27 102.7 3.22 60.81 7.35 1585 8 53.41 57.5 4.2 95.6 10 14 77 23 138.1 2.85 53.34 6.73 1629 6 51.01 79.2 5.5 93.4 11 12.6 72 28 115.4 1.58 57.22 6.78 1495 7 57.67 55.4 6.5 90.3 12 10.3 70 30 53.7 1.19 41.45 4.78 1506 8 52.34 70.4 4.5 93.7 13 13 73 27 50.5 3.48 45.84 6.78 1488 6 55.09 74.3 5.2 90.8 14 15.4 71 29 104.6 2.54 60.1 6.09 1549 6 56.27 61.9 5.8 92.8 15 10.7 78 22 61.3 2.77 62.55 7.33 1455 7 50.5 51.5 5.7 93.5 16 15.7 79 21 119.5 2.01 43.57 4.82 1530 8 55.61 61.8 4.5 92 17 15 79 21 67.7 1.9 55.63 5.7 1598 7 52.41 61.6 6.4 95.6 18 10.7 75 25 66.7 2.09 49.29 6.18 1497 7 56.14 68.8 5.4 91.5 19 11.4 70 30 142.1 3.23 64.39 5.51 1532 8 55.08 64.4 6 91.4 20 15 71 29 82 1.58 63.4 6.08 1553 6 57.11 64.8 5.9 90.2 As can be seen from Table 5, the tensile strength of the steel in the embodiments of the present invention is 1451~1630 MPa, all within the range of 1450~1650 MPa, the elongation is 6~8%, the hardness is 50~58 HRC, and the hardness retention rate at 300℃ is ≥90%. Compared with traditional 65Mn, 75Cr1 and ordinary 9CrSi saw blade steel, the wear resistance is improved by 51.2~79%, and the probability of tooth breakage is reduced by 4.2~6.8%. Its mechanical properties and high wear resistance and safety performance can meet the service conditions in the field of stone cutting.

[0037] It is hereby noted that the above embodiments are only for illustrating the technical concept and features of the present invention, and are not intended to limit the present invention. Any equivalent substitutions or modifications made without departing from the essence of the present invention fall within the protection scope of the present invention.

Claims

1. A high wear-resistant stone cutting saw blade base steel, characterized in that, The chemical composition of the steel plate by weight percentage is as follows: C: 0.75%~0.85%, Si: 0.5%~1.0%, Mn: 0.3%~1.1%, P≤0.02%, S≤0.01%, Als: 0.02%~0.06%, Cr: 1.0%~1.5%, Mo: 0.2%~0.5%, V: 0.05%~0.2%, B: 0.0005%~0.002%, W: 0.5%~1.0%, with the remainder being Fe and unavoidable impurities.

2. The high wear-resistant stone cutting saw blade base steel according to claim 1, characterized in that, The microstructure of the steel plate includes martensite and bainite, and contains a large amount of M7C3 and M. 23 C6 carbides, wherein the martensite content is 70-80% and the bainite content is 20-30%, wherein M7C3, M 23 C6 carbides have a size of 50–150 nm and a dislocation density ≥1.e+10 cm. -2 The proportion of large-angle grain boundaries is ≥40%, and the effective grain size is 4~8 μm.

3. The high wear-resistant stone cutting saw blade base steel according to claim 1, characterized in that, The steel plate has a tensile strength of 1450~1650 MPa, an elongation of 6~8%, a hardness of 50~58 HRC, a hardness retention rate of ≥90% at 300 ℃, and a finished steel plate thickness range of 10~16 mm.

4. A method for manufacturing the high wear-resistant stone cutting saw blade base steel according to any one of claims 1 to 3, comprising smelting, heavy pressing, rolling and online cooling, and normalizing heat treatment processes, characterized in that, Rolling and online cooling process: The continuous casting billet adopts the direct charging process, and the continuous casting billet is charged into the heating furnace at a furnace temperature of 400~700 ℃ and held for 1~2 h; the heating rate of the billet is controlled at 1~4 ℃ / min during the subsequent heating process; the heating temperature is 1160~1260 ℃ and held for 3~5 h; The initial rolling temperature is 1140~1240 ℃, the average reduction per pass is 5%~10%, and the final rolling temperature is 760~900 ℃; after rolling, online water cooling is used for cooling, with a water cooling rate of 8~12 ℃ / s. Normalizing heat treatment process: normalizing temperature is 760~860 ℃, normalizing holding time is 2.0~3.0 min / mm; stress relief tempering temperature is 150~300 ℃, stress relief tempering holding time is 2.0~3.0 min / mm.

5. The method for manufacturing the high wear-resistant stone cutting saw blade base steel according to claim 4, characterized in that, During the casting process, at the front end of the core solidification zone, a compression roller is used to apply heavy pressure, with a total reduction of ≥10 mm. The amount of secondary cooling water is controlled to make the surface cooling rate of the continuously cast billet 0.2~0.6 ℃ / s, the center cooling rate 0.05~0.2 ℃ / s, and the billet pulling speed 0.8~1.2 m / min.

Images