Ice breaker blade injection molding method

Abstract

The invention discloses an ice crusher blade injection molding method. The method comprises the steps of raw material preparation, injection molding, trimming, part placing and positioning, degreasing, sintering, shaping, magnetic polishing, drying, full-detection testing and finished product packaging. The ice crusher blade of a complex structure can be formed at a time, the material utilization rate and the production efficiency are improved, and meanwhile it is guaranteed that the blade product has high density, high hardness and excellent impact toughness; the whole technological process is clear in parameter, the defect rate caused by technological fluctuation is smaller than 1%, controllability is high, and the method is suitable for standardized production of the ice crusher blade.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of icebreaker blade forming, and particularly relates to an icebreaker blade injection forming method. BACKGROUND

[0002] The icebreaker blade is a key vulnerable part in the icebreaking equipment, and needs to have comprehensive mechanical properties such as high hardness, high wear resistance and high impact toughness. The traditional manufacturing method mainly adopts forging and subsequent machining or integral casting process. The forging method has low material utilization rate, complex subsequent machining process, high production cost, and is difficult to form the blade with complex internal cooling channels or lightweight structure. Although the casting method can form complex shapes, defects such as shrinkage holes and shrinkage porosity are easily generated in the blade, resulting in uneven product performance and insufficient toughness, and the blade is prone to breakage when subjected to high strength impact.

[0003] As a near-net forming technology, the metal powder injection molding technology (MIM) has been widely used in the field of small, complex and precise parts, but it still faces many challenges when used to prepare the icebreaker blade with high comprehensive performance requirements. For example, how to ensure uniform filling of the feeding material and avoid defects during the injection forming process of the large-size and special-shaped cross-section blade; how to control the deformation and obtain high density and fine-grained microstructure during the debinding and sintering process; and how to obtain the surface hardness and smoothness that meet the icebreaking working condition requirements through subsequent processing. There is a lack of a complete MIM process solution for the characteristics of the icebreaker blade in the prior art. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide an icebreaker blade injection forming method, which can form a complex structure blade at one time, improve material utilization rate and production efficiency, and at the same time ensure that the blade product has high density, high hardness and excellent impact toughness.

[0005] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0006] The present application provides an icebreaker blade injection forming method, comprising the following steps:

[0007] S1, raw material preparation: mixing stainless steel powder and binder according to a preset ratio to prepare metal injection forming feedstock (i.e. MIM feedstock) with a preset fluidity;

[0008] S2, injection forming: injecting the metal injection forming feedstock into a mold with a preset structure, forming under a preset injection parameter, and obtaining an icebreaker blade green body;

[0009] S3, trimming: removing the parting line burr and ejector pin burr on the icebreaker blade green body;

[0010] S4, the positioning of the swing: the trimming of the ice breaker blade green body is centrally placed on the ceramic plate, and the ice breaker blade green body and the ceramic plate are padded with the pad block distributed according to the preset direction, forming a component to be degreased;

[0011] S5, degreasing: the said component to be degreased is placed in the degreasing furnace, and the binder in the ice breaker blade green body is removed by adopting the preset degreasing program, and the green body after degreasing is obtained;

[0012] S6, sintering: the said green body after degreasing is transferred to the sintering furnace, and sintering is carried out by adopting the preset sintering program, and the densified ice breaker blade semi-finished product is obtained;

[0013] S7, shaping: the said ice breaker blade semi-finished product is transferred to the shaping mold on the shaping machine for shaping treatment;

[0014] S8, magnetic polishing: the ice breaker blade semi-finished product after shaping is subjected to magnetic polishing treatment to remove surface defects;

[0015] S9, drying: the ice breaker blade semi-finished product after magnetic polishing is placed in the oven for drying treatment, and the ice breaker blade finished product is obtained;

[0016] S10, full inspection test and finished product packaging: the ice breaker blade finished product after drying is subjected to size accuracy, appearance quality and mechanical property detection, and the qualified ice breaker blade finished product is screened out, packaged according to the preset packaging method, and the manufacturing is completed.

[0017] As a specific technical scheme of the application, in step S1, the stainless steel powder is 17-4PH stainless steel powder with a particle size of 5μm~20μm; the binder is a paraffin-polyvinyl alcohol blend, paraffin accounts for 55%~65% of the total mass of the binder, and polyvinyl alcohol accounts for 35%~45% of the total mass of the binder; the mixing mass ratio of the stainless steel powder and the binder is 90:10~95:5, the mixing temperature is 60℃~80℃, the stirring speed is 400rpm~600rpm, and the mixing time is 25min~35min.

[0018] As a specific technical scheme of the application, in step S2, the number of the mold cavity of the mold is 1~4, and the mold material is H13 hot work die steel; the preset injection parameters include: machine tonnage is 120T~150T, front mold temperature is 80℃~100℃, rear mold temperature is 80℃~90℃, injection cycle is 25s~30s, injection pressure is 110Bar~130Bar, and injection speed is 20mm / s~40mm / s; the green body density of the ice breaker blade green body is 5.3g / cm³~5.34g / cm³.

[0019] As a specific technical solution of the present invention, in step S3, the ice-breaking machine blade blanks after trimming are neatly arranged on a clean plastic tray; each plastic tray has 5 layers, and each layer has 6 ice-breaking machine blade blanks.

[0020] As a specific technical solution of the present invention, in step S4, the ceramic plate has a size of 115mm. 125mm The ceramic plate is 3mm thick and its surface is cleaned of dirt and dust with a brush before use; the pad is an arc-shaped ceramic pad with a specification of R53mm. R36.8mm 2.5mm; one ice-breaking machine blade blank and 4-8 pads are placed on one ceramic plate, and each pad is arranged in a circumferential array and cannot protrude from the outer side wall of the ice-breaking machine blade blank; the flat holes on the central column of the ice-breaking machine blade blank are distributed downwards.

[0021] As a specific technical solution of the present invention, in step S5, the preset degreasing program includes: the degreasing temperature is set to 120℃~130℃, the acid passage time is set to 570min~630min, the acid passage amount is set to 2.5g / min~3.5g / min, and the washing time is set to 90min; the degreasing process is carried out twice, and after the degreasing process, the degreasing rate is ≥6.95%, and the destructive test verifies that there are no undegreased green blanks in the blanks. The destructive test is to extract 1~2 blanks from the innermost middle layer of the degreasing furnace, manually crush them and observe the internal state.

[0022] As a specific technical solution of the present invention, in step S6, the preset sintering program includes: a sintering temperature of 1300℃~1350℃, a heating rate of 4℃ / min~6℃ / min, a holding time of 1.5h~2.5h, and a vacuum degree ≤10 in the sintering furnace. -3 Pa; the sintered density of the ice-breaking machine blade semi-finished product is ≥7.6g / cm³, the hardness is 30~40HRC, the single weight is 90.6g~91.2g, and the appearance is free from cracks, dirt, excess material, missing material, bulges, melting, deformation and sticking defects.

[0023] As a specific technical solution of the present invention, in step S7, the shaping pressure is set to 1.5MPa~3MPa, the holding time is set to 1s~3s, and the surface flatness of the shaped icebreaker blade semi-finished product reaches 0.2.

[0024] As a specific technical solution of the present invention, in step S8, the parameters of the magnetic polishing process include: the polishing needle specification is... 1.2mm The polishing solution is 200ml~300mL, the polishing speed is 25rpm~35rpm, and the total polishing time is 18min~24min, of which the left turn time is 9min~12min and the right turn time is 9min~12min.

[0025] As a specific technical solution of the present invention, in step S9, the parameters of the drying process include: drying temperature of 115℃~135℃, drying time of 4min~8min, and the surface of the dried ice-breaking machine blade is free from dirt, water stains, rust, dents and damage.

[0026] Compared with the prior art, the present invention provides an injection molding method for icebreaker blades, which has the following beneficial effects:

[0027] (1) Near net-shape forming, high efficiency and low cost: Using MIM technology, icebreaker blades with complex structures (such as those with internal flow channels and irregular curved surfaces) can be formed in one go, which greatly reduces the amount of machining and the material utilization rate is as high as 95% or more (compared to <50% for traditional cutting machining), significantly reducing production costs and processing cycles.

[0028] (2) Uniform structure and excellent performance: Through optimized feeding formula and sintering process, the 17-4PH stainless steel is sintered at 1300℃~1350℃, and the resulting blade has a dense microstructure and fine grains with a density ≥7.6g / cm³ and a hardness ≥30HRC, which is superior to traditional cutting parts, so that the blade has both high hardness and high wear resistance.

[0029] (3) Precise deformation control: Through the unique “positioning” step, special ceramic pads are used to constrain the blades during degreasing and sintering, which effectively prevents product warping and deformation caused by gravity or internal stress release, and ensures the dimensional accuracy of the product.

[0030] (4) Good surface quality: The magnetic polishing process can polish the complex surface of the blade without dead angles and uniformly, obtain excellent surface smoothness, reduce the adhesion of ice chips, and improve ice breaking efficiency and service life.

[0031] (5) Strong process controllability: Through gradient degreasing, vacuum sintering and full inspection process, the parameters of the entire process are clear, the defect rate caused by process fluctuation is <1%, the controllability is high, it is suitable for large-scale and standardized production, and the product consistency is good. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a process flow diagram of the present invention;

[0034] Figure 2 A first-view photograph of the GMMP0500 icebreaker blade manufactured according to Example 1.

[0035] Figure 3 A second-view photograph of the GMMP0500 icebreaker blade manufactured in Example 1.

[0036] Figure 4 This is a full inspection image of the GMMP0500 icebreaker blade manufactured in Example 1. Detailed Implementation

[0037] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0038] refer to Figure 1 This invention provides a method for injection molding icebreaker blades, comprising the following steps:

[0039] S1. Raw material preparation: Stainless steel powder and binder are mixed in a preset ratio to prepare a metal injection molding feed (i.e., MIM feed) with preset flowability.

[0040] S2. Injection molding: The metal injection molding feed is injected into a mold with a preset structure, and molding is performed under preset injection parameters to obtain a green icebreaker blade blank.

[0041] S3. Trimming: Remove the burrs from the parting line and ejector pins on the icebreaker blade blank;

[0042] S4. Positioning of the component: Place the trimmed ice-breaking machine blade blank in the center on the ceramic plate, with pads distributed in a preset direction between the ice-breaking machine blade blank and the ceramic plate to form the component to be degreased.

[0043] S5. Degreasing: Place the component to be degreased in a degreasing furnace and use a preset degreasing program to remove the binder in the green blank of the icebreaker blade to obtain a degreased green body.

[0044] S6. Sintering: The degreased green body is transferred to a sintering furnace and sintered at high temperature using a preset sintering program to obtain a densified icebreaker blade semi-finished product.

[0045] S7. Shaping: Transfer the semi-finished icebreaker blades to the shaping mold on the shaping machine for shaping.

[0046] S8. Magnetic polishing: The shaped icebreaker blade semi-finished product is subjected to magnetic polishing treatment to remove surface defects;

[0047] S9. Drying: Place the magnetically polished icebreaker blade semi-finished product in an oven for drying to obtain the finished icebreaker blade;

[0048] S10. Full inspection and finished product packaging: The dried ice-breaking machine blades are tested for dimensional accuracy, appearance quality and mechanical properties. Qualified ice-breaking machine blades are selected and packaged according to the preset packaging method to complete the manufacturing process.

[0049] In implementation, firstly, stainless steel powder and binder are mixed in a preset ratio during the material preparation stage to form a MIM feedstock with good flowability, laying the foundation for subsequent molding. Then, the MIM feedstock is injected into a custom mold corresponding to the shape of the icebreaker blade, forming a green icebreaker blade blank under specific injection parameters, achieving the initial molding of the complex structure of the icebreaker blade. Next, the parting line burrs and ejector pin burrs on the green icebreaker blade blank are removed to keep the product surface flat, smooth, and clean. Finally, the green icebreaker blade blank is centered and fixed to a ceramic plate using a positioning device to ensure subsequent... During hot working, the green body is subjected to uniform stress. Then, degreasing removes the binder from the green body, preventing defects caused by binder residue during subsequent sintering. Next, sintering densifies the degreased green body to achieve the target density under high temperature and vacuum, improving mechanical properties. Following this, it is transferred to a forming machine for pressure shaping, further compacting the product to correct its geometric dimensions and improve surface flatness, resulting in a smoother surface. Subsequently, magnetic polishing and drying optimize surface quality, removing burrs and preventing corrosion. Finally, qualified products undergo full inspection and are packaged to complete the entire manufacturing process. The entire process revolves around the requirements of precision, strength, and lightweight for icebreaker blades, organically connecting each stage of the MIM (Metal Injection Molding) process to form a standardized manufacturing system. This invention effectively solves the problems of low precision, difficulty in forming complex structures, and high cost in existing icebreaker blade manufacturing. Leveraging the near-net-shape advantages of MIM (Metal Injection Molding) technology, subsequent processing is reduced, increasing production efficiency by over 30% compared to traditional die casting and machining, thus meeting the goal of improving production efficiency. Simultaneously, material utilization reaches over 95%, and combined with optimized degreasing and sintering processes, overall manufacturing costs are reduced by 10%, satisfying cost control requirements. The entire process forms a complete quality control system, ensuring that the dimensional accuracy, structural strength, and surface quality of icebreaker blades meet standards, enhancing the company's technological level and market competitiveness in the icebreaker parts manufacturing field, and promoting the large-scale application of MIM technology in icebreaker manufacturing.

[0050] The invention ensures the molding performance of MIM feedstock by optimizing raw material selection and mixing process. In some specific embodiments, in step S1, the stainless steel powder is 17-4PH stainless steel powder with a particle size of 5μm~20μm; the binder is a paraffin-polyvinyl alcohol blend, with paraffin accounting for 55%~65% of the total mass of the binder and polyvinyl alcohol accounting for 35%~45% of the total mass of the binder; the mixing mass ratio of stainless steel powder to binder is 90:10~95:5, the mixing temperature is 60℃~80℃, the stirring speed is 400rpm~600rpm, and the mixing time is 25min~35min.

[0051] For raw material selection, 17-4PH stainless steel powder is chosen, with a particle size controlled between 5μm and 20μm. This particle size range ensures both the packing density of the powder and improves the mixing uniformity with the binder. The binder is a paraffin-polyvinyl alcohol blend, in which paraffin accounts for 55% to 65%, mainly to improve the flowability of the feedstock and ensure that the feedstock can fill the complex structure of the mold cavity during injection. Polyvinyl alcohol accounts for 35% to 45%, which can improve the strength of the green body and prevent damage to the green body during subsequent handling and placement.

[0052] In the mixing process, stainless steel powder and binder are mixed at a mass ratio of 90:10 to 95:5, and the mixing temperature is controlled at 60℃ to 80℃. This temperature range allows the binder to be in a molten state, reducing mixing resistance and preventing the binder from decomposing due to excessive temperature. The stirring speed is set to 400rpm to 600rpm and the mixing time is set to 25min to 35min to ensure that the stainless steel powder and binder are fully integrated to form a uniformly composed MIM feed and avoid defects such as insufficient material or air bubbles during injection due to uneven mixing.

[0053] This invention solves the problems of poor feed flowability and insufficient green strength in existing MIM processes by precisely controlling material composition and mixing technology. The selection of 17-4PH stainless steel powder provides a foundation for the excellent mechanical properties of icebreaker blades. The specific binder system ensures that the feed has both good flowability and green strength, allowing it to completely fill the complex mold cavity during injection molding. The breakage rate during green handling is reduced to below 1%. Uniform MIM feed can avoid defects such as cracking and bulging caused by component segregation during subsequent debinding and sintering, ensuring the quality of the finished icebreaker blades, while improving material utilization and further reducing manufacturing costs.

[0054] Regarding the pretreatment stage before material preparation, in order to improve the mixing effect and feeding performance, this invention pretreats the stainless steel powder and binder. Specifically, as a preferred embodiment, the 17-4PH stainless steel powder is vacuum dried before mixing at a temperature of 80℃~100℃ for 1h~2h; the binder is preheated to 50℃~70℃ before mixing.

[0055] For the pretreatment of stainless steel powder, vacuum drying is adopted, with a drying temperature of 80℃~100℃ and a drying time of 1h~2h. The vacuum environment can quickly remove the moisture adsorbed in the powder, avoiding the formation of air bubbles during the mixing process, which would cause pores in the feed. At the same time, the drying process can prevent the powder from clumping, ensure that the powder particles are evenly dispersed, and improve the mixing efficiency with the binder.

[0056] In the pretreatment of the binder, the binder is preheated to 50℃~70℃. This temperature can soften the binder, reduce the viscosity resistance during mixing, and facilitate full integration with stainless steel powder. At the same time, the fluidity of the preheated binder is improved, which can more evenly coat the powder particles, avoid component segregation during the mixing process, and ensure that the feed composition is uniform.

[0057] This invention effectively improves the quality and stability of MIM feedstock through pretreatment of powder and binder. Vacuum drying of stainless steel powder removes moisture and prevents agglomeration, avoiding air bubbles during feeding and reducing defects such as material shortages and porosity during injection molding. This improves the stability of green body density, meeting the goal of uniform green body quality. Preheating of the binder reduces mixing resistance and improves mixing uniformity, narrowing the fluctuation range of feedstock flowability. This ensures consistent filling of the mold cavity during injection, reducing green body quality differences caused by fluctuations in feedstock performance, and meeting the R&D requirements for material formulation optimization and improved molding performance. Simultaneously, the pretreatment process improves mixing efficiency, shortens mixing time, and reduces energy costs, helping companies improve production efficiency and product competitiveness, and laying a solid foundation for the stable operation of subsequent processes.

[0058] For the injection molding process, this invention ensures the quality of the icebreaker blade preform from two aspects: mold design and injection parameter settings. In some specific embodiments, in step S2, the number of cavities in the mold is 1 to 4, the mold material is H13 hot work die steel, and the mold is manufactured using electrical discharge machining and precision grinding processes; the preset injection parameters include: machine tonnage of 120T to 150T, front mold temperature of 80℃ to 100℃, rear mold temperature of 80℃ to 90℃, injection cycle of 25s to 30s, injection pressure of 110Bar to 130Bar, and injection speed of 20mm / s to 40mm / s; the preform density of the icebreaker blade preform is 5.3g / cm³ to 5.34g / cm³.

[0059] In terms of mold design, the number of mold cavities is set to 1 to 4 to match the size specifications and production needs of ice-breaking machine blades, thereby increasing output per unit time. The mold material is H13 hot work die steel, which has excellent high-temperature hardness and wear resistance, and can withstand temperature changes and mechanical wear during long-term injection, thus extending the service life of the mold. The mold manufacturing adopts electrical discharge machining and precision grinding processes to ensure the dimensional accuracy and surface finish of the mold cavities, laying the foundation for the precision of the ice-breaking machine blades.

[0060] Regarding injection parameters, the machine tonnage is selected as 120T~150T to match the molding requirements of the icebreaker blade preform, avoiding mold damage due to excessive tonnage or incomplete molding due to insufficient tonnage; the front mold temperature is controlled at 80℃~100℃, and the rear mold temperature is controlled at 80℃~90℃. Temperature difference control ensures that the feed material flows evenly and solidifies quickly in the mold, while preventing the preform from sticking to the mold; the injection cycle is set to 25s~30s, the injection pressure is set to 110Bar~130Bar, and the injection speed is set to 20mm / s~40mm / s. Through parameter coordination control, the feed material fills the mold cavity with stable pressure and speed within the specified time, ensuring that the density of the icebreaker blade preform is within the range of 5.3g / cm³~5.34g / cm³, avoiding porosity inside the preform.

[0061] This invention effectively improves the precision and production efficiency of icebreaker blade preforms through mold design and injection parameter optimization. The application of H13 hot work die steel extends mold life to 80,000-100,000 cycles, reducing mold replacement frequency and costs, and meeting the technical requirements for mold design optimization. Appropriate cavity design combined with reasonable injection parameters increases single-shift output, significantly improving production efficiency. The preform density of the icebreaker blade preform is 5.3g / cm³~5.34g / cm³, ensuring that the preform is not easily deformed during subsequent degreasing and sintering processes. This guarantees the dimensional accuracy and mechanical properties of the finished icebreaker blade, reduces the scrap rate due to preform quality issues, further lowers overall manufacturing costs, and enhances the market competitiveness of the company's products.

[0062] Furthermore, this invention focuses on the design of the mold cooling system and the standardization of the start-up process to ensure the stability of injection molding and the quality of the green blank. As a preferred embodiment, the mold in step S2 is also equipped with an independent cooling system, with the front mold cooling water channel and the rear mold cooling water channel designed separately. The diameter of the cooling water channel is 6mm~8mm, and the cooling water flow rate is 1.5L / min~2.5L / min. Before starting the machine, the residual material in the screw needs to be drained. After starting the machine, the first 10 mold products are discarded. After the products stabilize, samples are taken for the first inspection.

[0063] In terms of mold cooling system design, an independent cooling system is adopted, with the front mold cooling water channel and the rear mold cooling water channel designed separately. This allows for precise control of the temperature of the front mold and the rear mold, avoiding differences in green blank quality caused by uneven mold temperature. The diameter of the cooling water channel is set at 6mm~8mm. This diameter ensures a stable cooling water flow rate (1.5L / min~2.5L / min) and avoids the risk of blockage caused by excessively narrow water channels, ensuring uniform and continuous cooling effect and stabilizing mold temperature.

[0064] Regarding the start-up process, residual material in the screw must be drained before starting the machine to prevent uneven composition caused by mixing of different batches of feed, which would affect the quality of the green blank. The first 10 molds of products after starting the machine should be discarded because the mold temperature and injection parameters are not yet fully stable in the early stage of start-up, and the green blanks of the first 10 molds are prone to dimensional deviations or appearance defects. Discarding them can prevent unqualified green blanks from flowing into subsequent stages. After the products are stabilized, samples are taken for the first inspection. The first inspection confirms whether the green blank dimensions, density, appearance and other indicators meet the standards. Only after meeting the standards can it enter mass production to ensure the consistency of the quality of subsequent green blanks.

[0065] This invention significantly improves the stability of the injection molding process and the consistency of green blank quality through optimized mold cooling systems and standardized start-up procedures. The independent cooling system improves the temperature control precision of the front and rear molds, reduces the fluctuation range of green blank dimensions, and meets the goal of stable component dimensional accuracy. The rational cooling water circuit design avoids blockages, reduces mold maintenance frequency and costs, and extends mold life, meeting the requirements for mold design optimization. The standardized start-up procedure effectively avoids the impact of residual material contamination and initially unstable green blanks, increasing the green blank qualification rate to over 98%, reducing scrap rates in subsequent processes, and lowering production costs. Simultaneously, the stable production process facilitates automated mass production, improves production efficiency, and helps enterprises meet the large-scale supply demands of the icebreaker market.

[0066] In some specific implementations, in step S3, the trimmed ice-breaking machine blade blanks are neatly arranged on clean plastic trays; each tray has 5 layers, and each layer has 6 ice-breaking machine blade blanks. After completion, the product quantity is checked before proceeding to the next process.

[0067] Regarding the placement of the ornaments, this invention ensures the stability of subsequent degreasing and sintering processes through carrier selection and placement specifications. In some specific embodiments, in step S4, the ceramic plate has a diameter of 115mm. 125mm The ceramic slab is 3mm thick; before use, the surface should be cleaned with a brush to remove dirt and dust. The spacer is a curved ceramic spacer with a specification of R53mm. R36.8mm 2.5mm; one ice-breaking blade blank and 4-8 spacers are placed on one ceramic plate. The spacers are arranged in a circumferential array and should not protrude from the outer side wall of the ice-breaking blade blank; the flat holes on the central pillar of the ice-breaking blade blank are distributed downwards.

[0068] For the carrier selection, a 115mm specification was chosen. 125mm The 3mm ceramic plate has a low coefficient of thermal expansion, making it less prone to deformation under the high-temperature environment of degreasing and sintering, thus preventing the blank from shifting due to carrier deformation. Before use, the ceramic plate is cleaned of dirt and dust with a brush to prevent impurities from adhering to the surface of the green blank and affecting the surface quality and performance of the finished icebreaker blade.

[0069] Regarding the placement guidelines, one ice-breaking blade blank and 4-8 spacers should be placed on each ceramic plate. The spacers should be curved ceramic spacers with a diameter of R53mm. R36.8mm The 2.5mm spacers are arranged in a circumferential array and must not protrude from the outer wall of the ice-breaking blade blank. The flat holes on the central pillar of the ice-breaking blade blank face downwards. This ensures that the ice-breaking blade blank is stably and centrally fixed on the ceramic plate, improving space utilization, and also ensures that there is sufficient gap between the ice-breaking blade blank and the ceramic plate to allow the decomposition products of the binder during degreasing to be discharged smoothly and the heat to be transferred evenly during sintering. At the same time, all blanks must be placed in the same direction, and the flat holes on the central pillar of the ice-breaking blade blank must face downwards to ensure that each blank is subjected to the same stress and heat during hot processing, avoiding uneven forming due to differences in placement.

[0070] This invention solves the problems of green body deformation and uneven heating during degreasing and sintering through a reasonable placement design. The application of low-expansion coefficient ceramic plates effectively controls carrier deformation, reducing the green body position offset rate to below 0.5%; the surface cleaning step avoids the introduction of impurities, significantly reducing the surface defect rate of the icebreaker blades; the standardized placement spacing and direction ensure thorough degreasing and uniform sintering of the green body, reducing sintering cracks caused by incomplete degreasing and dimensional deviations caused by uneven heating, meeting the goal of ensuring the dimensional accuracy of parts meets usage requirements; at the same time, it improves the space utilization of ceramic plates, reduces energy consumption and costs in the hot processing stage, and realizes the requirements of process optimization and cost control.

[0071] Regarding the degreasing process, this invention ensures the degreasing effect through customized degreasing programs and detection methods. In some specific embodiments, in step S5, the preset degreasing program includes: the organic acid introduced is oxalic acid, the degreasing temperature is set to 120℃~130℃, the acid passage time is set to 570min~630min, the acid passage amount is set to 2.5g / min~3.5g / min, and the washing time is set to 90min; the degreasing process is carried out twice, and after the degreasing process, the degreasing rate is ≥6.95%, and the destructive test verifies that there are no undegreased green blanks. The destructive test involves extracting 1-2 green blanks from the innermost middle layer of the degreasing furnace and manually crushing them to observe the internal state.

[0072] In the degreasing process design, the degreasing temperature is set at 120℃~130℃. This temperature range allows the binder to decompose fully and avoids overheating and deformation of the green body. The acid passage time is set at 570min~630min, and the acid passage rate is set at 2.5g / min~3.5g / min. The organic acid helps to accelerate the discharge of binder decomposition products and improve degreasing efficiency. The cleaning time is set at 90min to remove residual acid and binder fragments from the surface of the green body and prevent impurities and defects from occurring during subsequent sintering.

[0073] For the degreasing effect test, a degreasing rate of ≥6.95% is set to ensure that most of the binder in the green body is removed. At the same time, a destructive test is used for verification. One or two green bodies from the innermost middle layer of the degreasing furnace are extracted, manually and slowly crushed, and their internal state is observed. If there are no undegreased green bodies inside (undegreased green bodies have a flocculent and loose structure), the degreasing is deemed qualified. This test method can effectively check the degreasing uniformity of green bodies in different positions in the furnace and avoid incomplete local degreasing caused by differences in furnace temperature and airflow.

[0074] This invention solves the problems of incomplete degreasing and poor degreasing uniformity in existing MIM processes by optimizing the degreasing process and conducting rigorous testing. Customized degreasing parameters ensure a stable degreasing rate above 6.95%, significantly reducing binder residue and effectively preventing defects such as cracking and bulging of the green body caused by thermal expansion of residual binder during subsequent sintering. This also improves the yield rate of the icebreaker blades. The application of destructive testing ensures consistent degreasing quality for all green bodies in the furnace, reducing batch defects caused by localized degreasing issues. Simultaneously, the rational design of acid purging and cleaning times ensures effective degreasing while avoiding energy waste and green body damage. This achieves the R&D goals of optimizing the forming process and controlling costs, laying a solid foundation for subsequent sintering densification.

[0075] Regarding the densification process during sintering, this invention improves the performance of the icebreaker blade blank through precise control of sintering parameters and quality management. In some specific embodiments, step S6 includes the following preset sintering program: sintering temperature set to 1300℃~1350℃, heating rate set to 4℃ / min~6℃ / min, holding time set to 1.5h~2.5h, and vacuum degree in the sintering furnace ≤10. -3 Pa; The sintered density of the ice-breaking machine blade semi-finished product is ≥7.6g / cm³, the hardness is 30~40HRC, the single weight is 90.6g~91.2g, and the appearance is free from cracks, dirt, excess material, missing material, bulges, melting, deformation and sticking defects.

[0076] In terms of sintering parameter design, the sintering temperature is set at 1300℃~1350℃. This temperature range allows the stainless steel powder particles to fully diffuse and combine, achieving a high degree of densification, while avoiding excessive temperature that could lead to melting and deformation of the billet. The heating rate is set at 4℃ / min~6℃ / min; slow heating reduces thermal stress caused by temperature differences within the billet, preventing cracking. The holding time is set at 1.5h~2.5h to ensure full bonding of the powder particles and improve the mechanical properties of the billet. The vacuum degree inside the sintering furnace is ≤10. - 3 Pa, the vacuum environment can prevent the blank from oxidizing when it comes into contact with air at high temperature, thus ensuring the surface quality and corrosion resistance of the icebreaker blade.

[0077] In terms of quality control, the density after sintering is set at ≥7.6g / cm³ to ensure that the green body has excellent mechanical properties; the weight is controlled at 90.6g~91.2g to meet the requirements of the ice-breaking machine; at the same time, strict requirements are imposed on the appearance, with no cracks, dirt, excess material, insufficient material, bulges, melting, deformation and sticking defects, to ensure that the appearance of the finished product meets the standards.

[0078] This invention significantly improves the mechanical properties and appearance quality of ice-breaking machine blades by optimizing sintering parameters and quality control. The sintered density is ≥7.6 g / cm³, giving the ice-breaking machine blades high strength and hardness. Vacuum sintering effectively prevents oxidation, eliminating the need for additional rust removal treatment and reducing subsequent processing costs. Strict appearance control ensures a finished product appearance defect rate of <1%, enhancing product market competitiveness. Simultaneously, the standardized single-weight design meets the weight requirements of ice-breaking machine components, helping companies launch more marketable products and driving technological advancements in the MIM process within the ice-breaking machine manufacturing field.

[0079] Regarding the shaping process, this invention employs a special shaping technique to correct the geometric dimensions and ensure good flatness of the ice-breaking blade surface. In some specific embodiments, in step S7, the shaping pressure is set to 1.5MPa~3MPa, the pressure holding time is set to 1s~3s, and the surface flatness of the shaped ice-breaking blade semi-finished product reaches 0.2.

[0080] During the shaping process, manual shaping is performed first to ensure that the cavity surface is clean and free of dirt, and to check that the upper mold is covered with the product. Then, the ice-breaking machine blade semi-finished product that needs to be shaped is placed into the cavity and positioned. The shaping pressure is set to 1.5MPa~3MPa, and the holding time is set to 1s~3s. This ensures that the shaping machine generates sufficient pressure to press the ice-breaking machine blade semi-finished product together, so that its surface flatness reaches 0.2.

[0081] This invention effectively improves the surface quality and strength of the finished icebreaker blades through a shaping process, meeting the goal of ensuring that the surface quality of the parts meets the requirements for use.

[0082] Regarding the magnetic polishing and drying processes, this invention optimizes the surface quality of the icebreaker blades and prevents corrosion by customizing the polishing process and drying parameters. In some specific embodiments, in step S8, the parameters for the magnetic polishing treatment include: the polishing needle specifications are... 1.2mm The polishing fluid volume is 200ml~300mL, the polishing speed is 25rpm~35rpm, and the total polishing time is 18min~24min, of which the left-hand rotation time is 9min~12min and the right-hand rotation time is 9min~12min. In step S9, the drying parameters include: drying temperature of 115℃~135℃, drying time of 4min~8min, and the surface of the dried icebreaker blade is free of dirt, water stains, rust, dents and damage.

[0083] For magnetic polishing, the following is selected: 1.2mm The 15mm polishing needle can penetrate deep into the complex structure of the icebreaker blade to remove residual burrs and oxide scale after sintering. The polishing fluid is added at a rate of 200ml~300mL to provide lubrication and cleaning during the polishing process, thereby improving the polishing effect. The polishing speed is set at 25rpm~35rpm to ensure that the polishing needle generates sufficient grinding force and to avoid deformation of the icebreaker blade due to excessive speed. The total polishing time is set at 18min~24min, including 9min~12min of left-hand rotation and 9min~12min of right-hand rotation. Bidirectional polishing ensures that the surface of the icebreaker blade is evenly stressed, avoiding local over-grinding or under-grinding caused by unidirectional polishing.

[0084] For the drying process, the drying temperature is set at 115℃~135℃. This temperature can quickly evaporate the moisture on the surface of the ice-breaking machine blades, while avoiding excessive temperature that could cause oxidation of the ice-breaking machine blades. The drying time is set at 4min~8min to ensure that the moisture is completely evaporated without damaging the structure of the ice-breaking machine blades. Ultimately, the surface of the dried semi-finished product is free of dirt, water stains, rust, dents, and damage, meeting the appearance quality requirements.

[0085] This invention effectively improves the surface quality and corrosion resistance of ice-breaking machine blades through optimized magnetic polishing and drying processes. Customized polishing parameters thoroughly remove sintered burrs and oxide scale, reducing surface roughness and significantly improving the feel and appearance of the ice-breaking blades, meeting the target of ensuring the surface quality of components meets usage requirements. The bidirectional polishing design ensures uniform polishing of all parts of the ice-breaking blade, avoiding localized defects and improving product consistency. Drying at specific temperatures and times completely removes surface moisture, preventing rust during subsequent storage and transportation, and extending the product's shelf life. The entire process requires no complex manual operation, enabling automated processing, improving production efficiency, reducing labor costs, and achieving cost control requirements.

[0086] For the full inspection testing stage, this invention uses multi-dimensional testing methods and clear indicators to screen qualified products and ensure the quality of products leaving the factory. In some specific embodiments, in step S10, dimensional accuracy testing uses calipers, a two-dimensional measuring instrument, and a height gauge. The testing items include the size of the ball, where the diameter tolerance is ±0.03~±0.05mm, the length tolerance is ±0.05~±0.08mm, and the angle tolerance is ±1°; the appearance quality inspection is a full inspection, screening out products without color difference, dirt, excess material, dents, scratches, missing material, bulges, and sintering cracks; the mechanical property testing includes hardness testing, with a hardness ≥30HRC.

[0087] For dimensional accuracy inspection, professional inspection tools such as calipers, 2D measuring instruments, height gauges, and pin gauges are used. Calipers are used for preliminary measurement of common dimensions, 2D measuring instruments are used for precise inspection of complex dimensions (such as the size of a ball), height gauges are used to inspect thickness, and pin gauges are used to inspect small apertures. The tolerance for the ball diameter is set to ±0.03~±0.05mm, the tolerance for the length is ±0.05~±0.08mm, and the tolerance for the angle is ±1° to ensure that the dimensions of the icebreaker blades meet the assembly requirements.

[0088] In terms of appearance quality inspection, a full inspection method is adopted. Professional inspectors are arranged to visually inspect each semi-finished product to screen out products without color difference, dirt, excess material, dents, scratches, missing material, bulges, and sintering cracks, so as to prevent products with appearance defects from entering the market.

[0089] In terms of mechanical performance testing, the focus is on hardness testing, with a target hardness of ≥30HRC. This is achieved using a Vickers hardness tester to ensure that the icebreaker blades have sufficient wear resistance and deformation resistance to meet the long-term use requirements of the icebreaker.

[0090] This invention establishes a comprehensive quality control system through multi-dimensional full-inspection testing, effectively ensuring the quality of finished ice-breaking machine blades. Dimensional accuracy testing utilizes specialized tools and clearly defined tolerances to ensure the assembly compatibility of the ice-breaking machine blades with other components, reducing assembly failure rates and meeting the goal of ensuring component dimensional accuracy meets usage requirements. Full-inspection of appearance eliminates products with defects from leaving the factory, improving user satisfaction and brand reputation. Hardness testing ensures the ice-breaking machine blades possess excellent mechanical properties, extending product lifespan and meeting the R&D requirements for component strength. Simultaneously, full-inspection testing can promptly identify anomalies in the production process, facilitating rapid adjustments to process parameters, reducing batch scrap, lowering production costs, and enhancing the company's quality control level and market competitiveness.

[0091] To make the technical solution of this application clearer and easier to understand, the present invention will be further described in detail below through detailed embodiments and in conjunction with the accompanying drawings.

[0092] Unless otherwise specified, the experimental methods used in the examples are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0093] Example 1

[0094] refer to Figures 1-4 This embodiment provides an injection molding method for icebreaker blades, used to manufacture GMMP0500 icebreaker blades, specifically including the following steps:

[0095] S1. Raw material preparation: 17-4PH stainless steel powder (particle size 10μm, purity 99.9%) was selected and vacuum dried in advance (90℃, 1.5h); the binder was a blend of paraffin (62wt%) and polyvinyl alcohol (38wt%), preheated to 60℃; the 17-4PH stainless steel powder and binder were mixed at a mass ratio of 93:7, the mixing temperature was set to 68℃, the stirring speed was set to 550rpm, and the mixing time was set to 35min to prepare a uniform metal injection molding feedstock (MIM feedstock). The feedstock flowability test (melt indexer, 190℃ / 2.16kg) showed a melt index of 15.4g / 10min, which meets the injection requirements.

[0096] S2. Injection Molding: The metal injection molding feedstock is injected into a mold with a pre-designed structure, and molding is performed under pre-defined injection parameters to obtain a green icebreaker blade blank with no defects such as missing material or bubbles. Specifically, the mold is made of H13 hot work die steel with one cavity; the injection molding machine has a tonnage of 130T, a front mold temperature of 90℃, a rear mold temperature of 85℃, an injection cycle of 27s, an injection pressure of 120Bar, and an injection speed of 30mm / s; the green density of the molded icebreaker blade blank is 5.32g / cm³.

[0097] S3. Trimming: Remove the parting line burrs and ejector pin burrs from the ice crusher blade blanks. After trimming, neatly arrange the ice crusher blade blanks on clean plastic trays; each tray has 5 layers, with 6 ice crusher blade blanks on each layer. After completion, check the product quantity before proceeding to the next process.

[0098] S4. Placement: Center the trimmed ice-breaking blade blank on the ceramic plate, with spacers arranged in a predetermined direction between the blade blank and the ceramic plate to form the assembly to be degreased. After placement, place the ceramic plate into a degreasing cart and check for displacement of the blank before pushing it into the degreasing furnace. The ceramic plate is 115mm in diameter. 125mm The ceramic slab is 3mm thick; before use, the surface should be cleaned with a brush to remove dirt and dust. The spacer is a curved ceramic spacer with a specification of R53mm. R36.8mm 2.5mm; one ice-breaking blade blank and six spacers are placed on one ceramic plate. The spacers are arranged in a circumferential array and cannot protrude from the outer side wall of the ice-breaking blade blank; the flat holes on the central pillar of the ice-breaking blade blank are distributed downwards.

[0099] S5. Degreasing: The components to be degreased are pushed into the degreasing furnace along with a dedicated degreasing cart. A preset degreasing program is used to remove the binder from the green blanks in the icebreaker blades, resulting in a degreased blank. The degreasing temperature is set to 125℃, the acid flow time to 600 min, the acid flow rate to 3 g / min (oxalic acid), and the washing time to 90 min. The degreasing process is performed twice, and the degreasing rate is 6.95% after degreasing. Two blanks from the innermost layer of the degreasing furnace are extracted for destructive testing to observe that the cross-section of the blanks is uniform and free of undegreased green blanks.

[0100] S6. Sintering: The degreased green body is transferred to a sintering furnace, which is a vacuum sintering furnace with a vacuum degree of 5×10⁻⁶. -4 Pa was subjected to high-temperature sintering using program #2, with a heating rate of 5℃ / min, held at 1320℃ for 2 hours, and cooled in the furnace to obtain a dense icebreaker blade semi-finished product with a density of 7.8g / cm³, a hardness of 35HRC, a single weight of 90.9g, and no defects such as cracks, melting, or deformation.

[0101] S7. Shaping: Transfer the semi-finished icebreaker blade to the shaping mold on the shaping machine for shaping. The shaping pressure is set to 2MPa, and the holding time is set to 2s. The surface flatness of the upper and lower planes of the shaped semi-finished icebreaker blade reaches 0.2. Visual inspection shows no deformation, indentations, or damage.

[0102] S8. Magnetic Polishing: Magnetic polishing is applied to the shaped icebreaker blades to remove surface defects. Specifically, the polishing needle specifications are... 1.2mm 15mm, polishing liquid addition is 250mL, polishing speed is 30rpm, and total polishing time is 20min (10min left turn + 10min right turn).

[0103] S9. Drying: Place the magnetically polished icebreaker blade semi-finished product in an oven and dry it at 125℃ for 6 minutes to obtain the finished icebreaker blade. Visually inspect the surface of the finished icebreaker blade after drying to ensure that there are no defects such as dirt, water stains, rust, dents, or damage.

[0104] S10, Full Inspection Test: (e.g.) Figure 4 As shown, the dried ice-breaking machine blades were tested for dimensional accuracy, appearance quality, and mechanical properties to select qualified blades. Specifically, a two-dimensional measuring instrument was used to measure the dimensions of the spheres, specifically sphere 4 (…). The 8mm +0 / -0.03mm and ball mark 5 (full circumference flatness 0.2) meet the requirements; the appearance inspection showed no color difference, dirt, excess material, dents, scratches, missing material, bulges and sintering cracks; the hardness test result was 35HRC; the pass rate was 99%.

[0105] S11. Finished Product Packaging: Package the product according to the pre-designed packaging method to complete manufacturing. Specifically, use 320mm... 400mm Place 0.07mm colorless PE bags inside the carton, then add dividers. Wrap each product with foam, place 12 products per layer, then add dividers, for a total of four layers, 48 ​​products per carton. Add dividers only after the top layer is filled before sealing the carton. Label each carton with the product name, model, date, quantity, etc. Pack the entire carton neatly, stacking them on pallets. Pallets should be stacked neatly, with a height of less than 8 layers. If a pallet is less than 7 layers high, it is permissible to stack the carton with the vehicle, ensuring a height of less than 7 layers. Take precautions against oil and water during transportation.

[0106] The above embodiments demonstrate that the molding method of this application can stably produce icebreaker blades, and the product precision, strength and pass rate all meet industry requirements, making it suitable for industrial mass production applications.

[0107] The above embodiments are merely illustrative of the concept and technical solution of the present invention and are not intended to limit the present invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

[0108] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for injection molding ice-breaking machine blades, characterized in that, Includes the following steps: S1. Raw material preparation: Mix stainless steel powder and binder in a preset ratio to prepare a metal injection molding feed with preset flowability. S2. Injection molding: The metal injection molding feed is injected into a mold with a preset structure, and molding is performed under preset injection parameters to obtain a green icebreaker blade blank. S3. Trimming: Remove the burrs from the parting line and ejector pins on the icebreaker blade blank; S4. Positioning of the component: Place the trimmed ice-breaking machine blade blank in the center on the ceramic plate, with pads distributed in a preset direction between the ice-breaking machine blade blank and the ceramic plate to form the component to be degreased. S5. Degreasing: The component to be degreased is placed in a degreasing furnace, and a preset degreasing program is used to remove the binder in the icebreaker blade blank to obtain a degreased blank. S6. Sintering: The degreased green body is transferred to a sintering furnace and sintered using a preset sintering program to obtain a densified icebreaker blade semi-finished product. S7. Shaping: Transfer the icebreaker blade semi-finished product to the shaping mold on the shaping machine for shaping treatment; S8. Magnetic polishing: The shaped icebreaker blade semi-finished product is subjected to magnetic polishing treatment to remove surface defects; S9. Drying: Place the magnetically polished icebreaker blade semi-finished product in an oven for drying to obtain the finished icebreaker blade; S10. Full inspection and finished product packaging: The dried ice-breaking machine blades are tested for dimensional accuracy, appearance quality and mechanical properties. Qualified ice-breaking machine blades are selected and packaged according to the preset packaging method to complete the manufacturing process.

2. The injection molding method for icebreaker blades according to claim 1, characterized in that, In step S1, the stainless steel powder is 17-4PH stainless steel powder with a particle size of 5μm to 20μm; the binder is a paraffin-polyvinyl alcohol blend, with paraffin accounting for 55% to 65% of the total mass of the binder and polyvinyl alcohol accounting for 35% to 45% of the total mass of the binder; the mixing mass ratio of the stainless steel powder to the binder is 90:10 to 95:5, the mixing temperature is 60℃ to 80℃, the stirring speed is 400rpm to 600rpm, and the mixing time is 25min to 35min.

3. The injection molding method for icebreaker blades according to claim 1, characterized in that, In step S2, the number of cavities in the mold is 1 to 4, and the mold material is H13 hot work die steel; the preset injection parameters include: machine tonnage of 120T to 150T, front mold temperature of 80℃ to 100℃, rear mold temperature of 80℃ to 90℃, injection cycle of 25s to 30s, injection pressure of 110Bar to 130Bar, and injection speed of 20mm / s to 40mm / s; the green density of the icebreaker blade green blank is 5.3g / cm³ to 5.34g / cm³.

4. The injection molding method for icebreaker blades according to claim 1, characterized in that, In step S3, the trimmed ice-breaking machine blade blanks are neatly arranged on clean plastic trays; each plastic tray has 5 layers, and each layer has 6 ice-breaking machine blade blanks.

5. The injection molding method for icebreaker blades according to claim 1, characterized in that, In step S4, the ceramic plate has a diameter of 115mm. 125mm The ceramic plate is 3mm thick and its surface is cleaned of dirt and dust with a brush before use; the pad is an arc-shaped ceramic pad with a specification of R53mm. R36.8mm 2.5mm; one ice-breaking machine blade blank and 4-8 pads are placed on one ceramic plate, and each pad is arranged in a circumferential array and cannot protrude from the outer side wall of the ice-breaking machine blade blank; the flat holes on the central column of the ice-breaking machine blade blank are distributed downwards.

6. The injection molding method for icebreaker blades according to claim 1, characterized in that, In step S5, the preset degreasing program includes: the degreasing temperature is set to 120℃~130℃, the acid passage time is set to 570min~630min, the acid passage amount is set to 2.5g / min~3.5g / min, and the washing time is set to 90min; the degreasing process is performed twice, and after the degreasing process, the degreasing rate is ≥6.95%, and the destructive test verifies that there are no undegreased green billets. The destructive test involves extracting 1~2 billets from the innermost middle layer of the degreasing furnace and manually crushing them to observe the internal state.

7. The injection molding method for icebreaker blades according to claim 1, characterized in that, In step S6, the preset sintering program includes: a sintering temperature of 1300℃~1350℃, a heating rate of 4℃ / min~6℃ / min, a holding time of 1.5h~2.5h, and a vacuum degree ≤10 in the sintering furnace. -3 Pa; the sintered density of the ice-breaking machine blade semi-finished product is ≥7.6g / cm³, the hardness is 30~40HRC, the single weight is 90.6g~91.2g, and the appearance is free from cracks, dirt, excess material, missing material, bulges, melting, deformation and sticking defects.

8. The injection molding method for icebreaker blades according to claim 1, characterized in that, In step S7, the shaping pressure is set to 1.5MPa~3MPa, the holding time is set to 1s~3s, and the surface flatness of the shaped icebreaker blade semi-finished product reaches 0.

2.

9. The injection molding method for icebreaker blades according to claim 1, characterized in that, In step S8, the parameters of the magnetic polishing process include: the polishing needle specifications are... 1.2mm The polishing solution is 200ml~300mL, the polishing speed is 25rpm~35rpm, and the total polishing time is 18min~24min, of which the left turn time is 9min~12min and the right turn time is 9min~12min.

10. The injection molding method for icebreaker blades according to claim 1, characterized in that, In step S9, the parameters of the drying process include: drying temperature of 115℃~135℃, drying time of 4min~8min, and the surface of the dried ice-breaking machine blade is free from dirt, water stains, rust, dents and damage.

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