KR102030804B1 - Ax and method for manufacturing the same - Google Patents

Abstract

The present invention provides an ax and a manufacturing method for the same. The manufacturing method for the same includes: i) a step of providing an ax body; ii) a step of heating the ax body at the temperature of 750-800°C; iii) a step of soaking only a part of an ax blade in a coolant and firstly hardening the ax blade for a first predetermined time; iv) a step of firstly tempering the ax body for a second predetermined time by heat conduction of an ax back having the temperature of 350-400°C by picking the ax body out from the coolant; v) a step of secondly tempering the whole ax blade for a third predetermined time by soaking the whole ax blade in the coolant; vi) a step of secondly tempering the ax body for a fourth predetermined time by residual heat of the ax having the temperature of 350-450°C by picking the ax body out from the coolant; and vii) a step of soaking the ax body in the coolant and cooling the ax body. The ax body includes the ax back and the ax blade. The ax body includes: 0.5-2.5 wt% of C; 10-20 wt% of Cr; 0-1 wt% (excluding 0) of Si; 0-1 wt% (excluding 0) of Mn; 0-3 wt% (excluding 0) of Mo; 0-0.1 wt% (excluding 0) of N; 0-0.1 wt% (excluding 0) of Ti; and residues including Fe and inevitable impurities.

Description

Ax and its manufacturing method {AX AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to an ax and a method for producing the same. In more detail, this invention relates to the ax which can be used for firefighting by improving the intensity | strength, and its manufacturing method.

For a quick life-saving, etc. in the event of a building fire, a fire axe is required to enter the building quickly. Firefighters buy and use axes to suit their personal characteristics. These axes are not specially designed for fire fighting but are used for general purposes and are mainly imported from abroad.

The buildings are now made of concrete or steel rather than wooden houses. In particular, since the front door is made of steel, it must be broken and entered inside in an emergency. However, the ax currently supplied to the fire department is weak in strength, and thus there is a limit to tearing or breaking the front door or the steel door of the vehicle.

Korean Patent Publication No. 2005-0088845

The ax which improved the strength is provided. Moreover, the manufacturing method of the above-mentioned ax is provided.

A method of manufacturing an ax according to an embodiment of the present invention comprises i) axe and ax blade, 0.5wt% to 2.5w% C, 10wt% to 20wt% Cr, greater than 0 and less than 1wt% Si , An ax body containing greater than 0 and less than 1 wt% Mn, greater than 0 and less than 3 wt% Mo, greater than 0 and less than 0.1 wt% N, greater than 0 and less than 0.1 wt% Ti, residual iron and other impurities Providing, ii) heating the ax body to 750 ° C. to 800 ° C., iii) immersing only a portion of the ax blade in the coolant and first quenching for a first predetermined time, iv) removing the ax body from the coolant 350 Performing a first tempering treatment for a second predetermined time by thermal conduction of an ax lamp having a temperature ranging from 400 ° C. to 400 ° C., v) immersing the entire ax blade in a coolant for a second quenching time for a third predetermined time, vi ) The ax body is removed from the coolant, such as an ax having a temperature of 350 ° C to 450 ° C. A first step, and vii) body axes of the secondary tempering treatment for 4 hours by the heat exchanger settings and a step of cooling by immersion in the coolant.

The first preset time is 1 second to 2 seconds in the first quenching step, and the second preset time is 2 seconds to 3 seconds in the first tempering process, and the third preset time in the second quenching step. Is 2 seconds to 3 seconds, and the fourth preset time in the second tempering process may be 3 seconds to 4 seconds.

Providing the ax body may include: i) providing a steel sheet, and ii) folding and pressing the steel sheet a plurality of times and then cutting it.

Ax according to an embodiment of the present invention can be prepared by the method described above. The ax further comprises: i) a handle pipe welded and connected to the ax body, and ii) an opening and closing stopper coupled to one end of the handle pipe. A rope or oxygen concentration meter may be inserted inside the handle pipe.

The ax further includes a handle pipe welded and connected to the ax body. A plurality of spanner grooves is formed on the upper side of the axe, and a square wrench groove larger than each of the plurality of spanner grooves is formed on the lower side of the ax body opposite the plurality of spanner grooves with the handle pipe therebetween.

Axes with good strength can be made suitable for fire fighting. The strength of the ax is so good that it can easily break hard materials such as iron gates at the fire site. In other words, the strength of the ax is sufficient to quickly break or tear off the iron front door or vehicle door. Moreover, since ax is excellent in durability, ax can be used for a long time. Axes having a high hardness, high cutting ax blade, high strength and high toughness axe and the like can be produced. Therefore, the ax is suitable for use in harsh environments.

1 is a schematic perspective view of a firefighting ax according to a first embodiment of the present invention.
2 is a schematic flowchart of a method of manufacturing the ax of FIG.
3 to 5 schematically show some steps of the manufacturing method of the ax of FIG. 2, respectively.
6 and 7 are schematic partial perspective views of the fire ax according to the second and third embodiments of the present invention, respectively.
8 is a schematic perspective view of a fire ax according to a fourth embodiment of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an,” and “the” include plural forms as well, unless the context clearly indicates the opposite. As used herein, the term "comprising" embodies a particular characteristic, region, integer, step, operation, element, and / or component, and other specific characteristics, region, integer, step, operation, element, component, and / or group. It does not exclude the presence or addition of.

Unless defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Commonly defined terms used are additionally interpreted to have a meaning consistent with the related technical literature and the presently disclosed contents, and are not interpreted in an ideal or very formal sense unless defined.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 schematically shows an ax 100 according to a first embodiment of the invention. Ax 100 may be used for fire fighting. The ax 100 may be manufactured as a small one-handed axe or a medium-sized two-handed axe by adjusting its size, and can be efficiently applied in the field according to the fire suppression object. In addition, the structure of the ax 100 of FIG. 1 is only for illustration of this invention, Comprising: This invention is not limited to this. Therefore, the structure of the ax 100 can be modified into other forms.

As shown in FIG. 1, the ax 100 includes an ax body 10, a handle pipe 20, and a stopper 30 for opening and closing. The ax body 10 and the handle pipe 20 are welded to each other through the welding portion 15 is firmly connected. The ax main body 10 and the handle pipe 20 are coupled in a direction perpendicular to each other with respect to the direction of extension so that the force falling in use is transmitted to the maximum. Opening and closing plug 30 is detachably coupled to one end of the pipe for handle 20. Here, the opening and closing plug 30 may be omitted. In addition, the ax 100 may further include other components.

The ax body 10 includes an ax lamp 103 and an ax blade 101. The ax lamp 103 should increase its tensile strength to have excellent toughness, and the ax blade 101 should increase its hardness to have excellent machinability. For this reason, the ax lamp 103 has a larger thickness than the ax blade 101 as a whole. The ax blade 101 is thinly formed in order to split the objects taken with the ax 10 well. Axe 103 is formed somewhat thick to balance the ax 10 when using. The ax lamp 103 and the ax blade 101 are formed in a direction away from each other side by side in the x-axis direction.

Pickaxe portion 103a is formed at the end of ax lamp 103. That is, as the end portion of the ax lamp 103 is bent, its width gradually narrows to form the pickaxe portion 103a. Using the pickaxe 103a, it is possible to quickly break or tear off the metal front door or the vehicle door at the fire site. In addition, the pickaxe (103a) also serves as a claw hammer, it can be used to remove the nails and other connectors of the wooden building.

Spanner grooves 105 are formed side by side in the x-axis direction on the upper side of the ax lamp 103. The spanner grooves 105 include a first spanner groove 105a, a second spanner groove 105b, and a third spanner groove 105c. The third spanner groove 105c is larger than the second spanner groove 105b, and the second spanner groove 105b is larger than the first spanner groove 105a. Therefore, spanner grooves 105 may be used to disassemble nuts of various sizes. That is, firefighters may use spanner grooves 105 to disassemble and remove the structure at the fire site. Since the spanner grooves 105 are formed in a hexagonal shape, the hexagonal nuts may be inserted into and rotated in the spanner grooves 105 to be fastened and separated. Preferably, the diameters of the first spanner groove 105a, the second spanner groove 105b, and the third spanner groove 105c may be 17 mm, 19 mm, and 24 mm, respectively. Spanner grooves 105 of various dimensions may be used to join or separate hex nuts.

The grab pipe 20 is made of metal, preferably iron alloy or aluminum alloy. The handle of a common ax is made of wood, which is vulnerable to fire and weak. Therefore, the handle may be damaged during the fire suppression process. In the first embodiment of the present invention, in consideration of this point, the pipe 20 for the handle is made of metal.

The square wrench grooves 107 are formed on the lower side of the ax body 10 opposite the spanner grooves 105 with the handle pipe 20 therebetween. That is, the handle pipe 20 is positioned between the square wrench groove 107 and the spanner grooves 105. The size of the square wrench groove 107 is larger than the size of each spanner groove 105. The square wrench groove 107 may be used to open a valve for supplying water to the fire brigade. Since the fire brigade for fire fighting is installed on the road, it is possible to supply water quickly by opening the valve using the ax 100 when arriving at the fire site. Hereinafter, the manufacturing method of the ax main body 10 is demonstrated in detail through FIG.

FIG. 2 schematically shows a flowchart of the manufacturing method of the ax 100 of FIG. 1. The manufacturing method of the ax 100 of FIG. 2 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the manufacturing method of the ax 100 can be changed differently. In FIG. 2, the hardness and strength of the ax are improved by applying a heat treatment method for providing a cooling rate difference to the ax blade and the ax.

As shown in FIG. 2, the manufacturing method of the ax 100 includes providing an ax body including an ax and the ax blade (S10), heating the ax body (S20), and only a part of the ax blade 1. Primary quenching step (S30), the first tempering treatment by heat conduction of the ax blade (S40), the second quenching of the entire ax blade (S50), the secondary body tempering treatment using the residual heat such as ax Step (S60), the step of cooling the ax body (S70) and the step of coupling the ax body and the pipe for the handle (S80). In addition, the manufacturing method of the ax 100 may further include other steps as necessary.

First, in step S10, the ax body is provided. The manufacturing method of an ax differs from the general heat processing method of the steel in the heat processing of the ax which is the finished product for which the use was already decided. Axes have a mixture of ax blades and axes that require mutually opposite organization and properties. Therefore, when considering the structure, a special heat treatment process different from the general steel is required.

Corrosion resistance high carbon steel can be used as a raw material of an ax body. More specifically, the ax body has 0.5wt% to 2.5w% carbon (C), 10wt% to 20wt% chromium (Cr), greater than 0 and less than 1wt% silicon (Si), greater than 0 and less than 1wt% Manganese (Mn), greater than 0 and less than 3wt% molybdenum (Mo), greater than 0 and less than 0.1wt% nitrogen (N), greater than 0 and less than 0.1wt% titanium (Ti), balance iron and other impurities Include. In addition, the ax body may further include other elements as necessary.

Carbon is added to secure the strength of the ax body. Carbon improves the hardness of the martensite structure contained in the ax body. Therefore, when the amount of carbon is too small, the strength of the ax body decreases. Conversely, if the amount of carbon is too large, as the ax blade is continuously worn using the ax body, the primary carbide, M ₇ C _3, may precipitate and become the starting point of corrosion. As a result, corrosion resistance of an ax main body falls and it becomes weak also to grinding | polishing.

Chromium is necessary to ensure the corrosion resistance of the ax body. However, when the amount of chromium is too large, the martensite transformation end temperature M _f is lowered. In this case, after quenching, the martensite transition may be excessively incomplete, leading to a decrease in the hardness of the ax body. Therefore, it is preferable to adjust the amount of chromium in the above-mentioned range. Preferably, the amount of chromium may be 15 wt% to 16 wt%.

Silicon lowers the martensite onset temperature (Ms). Silicon can reduce chromium oxide. However, when the amount of silicon is large, a high temperature curing effect may be generated that limits the possibility of deformation during processing of the axe. Therefore, it is necessary to control the addition amount appropriately.

Manganese is added to stabilize the tissue structure of the ax body. If the amount of manganese is too large, the amount of martensite becomes insufficient after quenching, and the strength of the ax body decreases.

Molybdenum improves hardenability and resistance to formulas and promotes the formation of M (C, N). However, the martensite transformation end temperature Mf which is expensive and contains too much molybdenum becomes low. Therefore, the amount of molybdenum is appropriately limited.

Nitrogen is needed to increase the hardness of the martensite constituting the axle tissue. When limiting the amount of carbon to avoid the formation of excessive precipitates, nitrogen can reinforce the hardness loss of the ax blades. Nitrogen also contributes to the improved corrosion resistance of the axe. If the amount of such nitrogen is too large, N ₂ bubbles may be formed and holes may be formed in the ax so that the amount of addition is limited.

Titanium produces more stable carbides and nitrides than chromium carbides and chromium nitrides, contributing to the stabilization of the ax. However, when the amount of titanium is added too much, it is possible to limit the hardness of martensite generated after quenching. Therefore, it is necessary to appropriately control the amount of titanium.

In step S10, a steel sheet is provided, which is folded and pressed a plurality of times, and then cut to provide an ax body. By overlapping a plurality of times, it is possible to realize a uniform and high-strength structure through a folding process. In other words, the steel sheet is heated by using a monolayer furnace or a high frequency induction furnace or the like, and then overlapped in multiple layers to produce a plate member having a width of 120 mm or more and a thickness of 10 mm or more. On the other hand, instead of changing the shape and size through a two-stage rolling process, it is possible to manufacture a plate material similar to the actual shape. And the board | plate material is cut by a laser in order to shape the ax main body. Partly machine the plate cut by the laser.

Next, in step S20, the ax main body is heated. More specifically, the ax body is heated to 700 ° C. to 800 ° C. for soaking. The ax is heated in this temperature range to give it an appropriate hardness, resulting in pearlite tissue. The temperature range can vary depending on the composition of the axe. If the heating temperature of the ax is too high, particles may grow and the heating temperature is adjusted to the above-mentioned range. The ax is charged into an annealing furnace and heated uniformly.

In step S30, only a part of the ax blade is immersed in the coolant to be first quenched. The first quenching time may be 1 second to 2 seconds. If the quenching time is too short or too long, martensite transformation of the immersion portion is unlikely to occur. Therefore, the quenching time is adjusted to the above-mentioned range. In addition, the quenching process is automatically controlled so that the quenching time can be quantified. This will be described in more detail with reference to FIG. 3.

FIG. 3 schematically illustrates a process of dipping a part of the ax blade in the coolant in step S30 of FIG. 2. The dipping process of the ax blade of FIG. 3 is only for illustrating the present invention, but the present invention is not limited thereto. Therefore, the dipping process of the ax blade can be modified in other forms.

As shown in FIG. 3, the ax main body 10 is gripped by the robot hand 80 to immerse the ax blade 101 in the cooling tank 90. The robot hands 80 are prepared in pairs and spaced apart from each other to hold the ax body 10. In order to immerse only a part of the ax blade 10 in the coolant C, the ax main body 10 is firmly gripped by the robot hand 80. The robot hand 30 is controlled to be movable up, down, left, and right, respectively, and can move the ax main body 10 freely. The coolant 95 is prepared in the cooling tank 90 to quench the ax blade 101. The ax blade 101 may be water cooled or oil cooled using water or oil as the coolant 95. Details of the robot hand 80 and the coolant 95 can be easily understood by those skilled in the art, and detailed descriptions thereof will be omitted.

The robot hand 80 is lowered in the direction of the arrow to immerse a part of the ax blade 101, that is, the end of the ax blade 101 by the coolant 95. Since the ax blade 101 is an arc, it is possible to quench the end of the ax blade 101 by rotating the ax blade 101 in the direction of the arrow. The ax main body 10 is precisely controlled by the robot hand 80 so that only a part of the ax blade 101 is accurately immersed in the coolant 95. Since the immersion process is made through an automated process, the ax body 10 can be manufactured uniformly without any quality difference.

Returning to FIG. 2 again, in step S40, the primary tempering process is performed by the heat conduction of the ax blade. More specifically, the ax main body is removed from the coolant and subjected to a primary tempering treatment by heat conduction such as an ax having a temperature of 350 ° C to 400 ° C. Here, the first tempering treatment may be performed for 2 to 3 seconds. This will be described in more detail below with reference to FIG. 4.

4 schematically shows a first tempering treatment process of the ax blade 10 of FIG. This tempering treatment step is merely to illustrate the present invention, but the present invention is not limited thereto. Thus, the tempering treatment process may be modified differently.

Cracking and torsion exist in the ax blade 101 due to the thermal stress according to the first quenching in step (S30). Therefore, the tempering treatment is required to remove the thermal stress of the ax blade 101. The tempering treatment immediately removes cracks and twists of the ax blade 101.

In order to increase the hardness of the ax blade 101, it is heated and then rapidly cooled to make the ax blade 101 into martensite structure. If the ax main body 10 is cooled, the martensite structure is also generated in the ax etc. 103, which adversely affects the toughness. Therefore, only a part of the ax blade 101 is locally quenched. The pearlite structure remains as it is in the ax lamp 103 and has excellent toughness.

As the martensite structure is formed on the blade blade 101 by cooling, a stress is generated. Therefore, tempering heat treatment is required for stress relief. If the temperature of the ax lamp 103 is sufficiently high, the same effect as the tempering treatment may be applied to the ax blade 101 by the heat conduction from the ax lamp 103 without additional heat treatment. That is, if the ax blade 10 is rapidly cooled and then left in the air, the tempering treatment effect can be imparted to the ax blade 101 by the heat conduction from the ax lamp 103, as indicated by the arrow in FIG. .

That is, for convenience, it actually corresponds to the ax main body 10, but as shown in the arrow of Fig. 4 shown elsewhere, by using the residual heat of the ax lamp 103, the ax blade 101 can be tempered immediately without an additional heating process. have. That is, the ax blade 101 is immediately tempered for 2 to 3 seconds by thermal conduction of the residual heat of the ax lamp 103 having a temperature of 350 ° C to 400 ° C. This temperature range may vary depending on the composition of the axe. Thereby, the crack and torsion of the ax blade 101 can be removed efficiently, and a separate tempering facility is not necessary. Although not shown in FIG. 4, the temperature of the ax lamp 103 is automatically measured using a non-contact infrared thermometer. Therefore, the tempering process can be automated and processed efficiently.

2, in step S50, the whole ax blade is immersed in a coolant to perform secondary quenching. Secondary quenching time may be from 2 seconds to 3 seconds. This will be described in more detail with reference to FIG. 5.

5 schematically illustrates a process of secondary quenching by dipping the entire ax blade 101 in the coolant 95. The quenching process of FIG. 5 is merely to illustrate the invention, but the invention is not limited thereto. Therefore, the quenching process can be modified in other forms.

As shown in FIG. 5, the robot hand 80 is lowered in the direction of the straight arrow to immerse the ax blade 101 in the coolant 95, and then rotate the robot hand 80 in the direction of the curved arrow to cool the entire ax blade 101. Can be immersed in). Although not shown in FIG. 5, the robot hand 80 is a multi-joint, such a task is possible.

When the ax blade 101 is immersed in this way, the vicinity of the boundary of the ax blade 101 is transformed into a composite structure of martensite and pearlite. That is, the structure of the connection part of martensite of the ax blade 101 and the pearlite of the ax main body 10 base material becomes dense, and is firm. On the contrary, when only the pearlite structure exists in the boundary of the ax blade 101, it is easy to be broken by an external shock. Therefore, a process for transforming this part into a complex tissue is needed. The rest of the process of secondary quenching is similar to the above-described primary quenching, and thus a detailed description thereof will be omitted.

2 again, in step S60, the ax blade is subjected to secondary tempering treatment using residual heat such as an ax having a temperature of 350 ° C to 450 ° C. Since all the processes are fast, the temperature of the ax lamp is kept constant without a great drop. In step S60, the ax is tempered for 3 to 4 seconds. Thermal conduction, such as an axe, can be used to relieve residual stress in the composite tissue. On the other hand, since the remaining process of step S60 is similar to step S40, a detailed description thereof will be omitted. On the other hand, although not shown in Figure 2, the aforementioned quenching process and tempering process may be repeated one or more times.

In step S70, the ax main body is immersed in a coolant to cool. That is, both the soaked ax and the quenched and tempered ax blades are cooled. As a result, the ax main body of the complex form provided with the ax blade etc. of the outstanding toughness, and the excellent hardness is possible. By incorporating heat treatments such as quenching, tempering and soaking to produce the ax body, the process is simplified and productivity can be improved.

In step S80, the ax main body and the handle pipe are combined to provide an ax. The ax body and the handle pipe are manufactured by inserting a handle pipe into a groove formed in the ax body and welding both. As a result, an ax having excellent strength can be produced. On the other hand, since an ax is used for firefighting, an ax can also be apply | coated with red paint.

6 partially shows an ax 200 according to a second embodiment of the invention. Since the structure of the ax 200 of FIG. 6 is similar to that of the ax 100 of FIG. 1, the same reference numerals are used for the same parts, and a detailed description thereof will be omitted.

As shown in FIG. 6, the emergency rope 40 may be inserted into the handle pipe 20. After inserting the emergency rope 40 into the handle pipe 20, the opening and closing plug 30 may be stably received by combining the direction of the dotted arrow with one end of the handle pipe 20. As a result, the firefighter can easily carry the emergency rope 40, which makes the fire fighting task easier.

Meanwhile, the rubber cover 22 may be attached to the outside of the handle pipe 20. When the firefighter uses the ax 200 at the fire site due to the frictional force by the rubber cover 22, the ax 200 may be stably gripped without slipping from the hand.

7 partially shows an ax 300 according to a third embodiment of the invention. Since the structure of the ax 300 of FIG. 7 is similar to that of the ax 200 of FIG. 6, the same reference numerals are used for the same parts, and a detailed description thereof will be omitted.

As shown in FIG. 7, the oxygen concentration measuring instrument 50 may be inserted into the handle pipe 20. The oxygen concentration measuring instrument 50 prevents a human accident at the fire site by sounding a buzzer or flashing a red lamp when the oxygen concentration in the surroundings is deficient. When the red lamp is flashing, a transparent window may be installed on the handle pipe 20 corresponding thereto to facilitate external observation, or the opening and closing plug 30 may be manufactured to be transparent.

The oxygen concentration meter 50 may be firmly received using a housing 501 of a suitable size inserted into the handle pipe 20 without gaps. That is, since the outer diameter of the frame 501 coincides with the inner diameter of the handle pipe 20, the oxygen concentration meter 50 is firmly stored inside the handle pipe 20 without flowing up, down, left, and right. After the oxygen concentration measuring instrument 50 is inserted, the opening and closing plug 30 may be screwed to one end of the handle pipe 20 to stably receive the oxygen concentration measuring instrument 50. To this end, a thread is formed at one end of the handle pipe 20.

On the other hand, if you want to remove the oxygen concentration measuring instrument 50, open the opening and closing plug 30, and pull the handle 503 by pulling. Oxygen concentration meter 50 operates on its own internal power supply. The detailed structure of the oxygen concentration measuring instrument 50 can be easily understood by those skilled in the art, and detailed description thereof will be omitted.

8 schematically shows a method of manufacturing the ax 400 according to the fourth embodiment of the present invention. The structure of this ax 400 is merely to illustrate the invention, but the invention is not limited thereto. Therefore, the structure of the ax 400 can be modified into other forms. In addition, since the ax 400 is similar to the ax 100 of FIG. 1, the same reference numerals are used for the same parts, and a detailed description thereof will be omitted.

As shown in FIG. 8, the ax 400 includes an ax body 14 and a handle pipe 24. The ax body 14 and the handle pipe 24 are integrally connected. The ax body 14 includes an ax blade 141 and an ax 143. Ax 143 is formed in the form of nail puller (143) can be used to pull the nail.

Hereinafter, the present invention will be described in more detail through experimental examples. These experimental examples are only for illustrating the present invention, and the present invention is not limited thereto. Accordingly, the present invention can be modified differently.

Experimental Example

10 axes containing 1 wt% carbon, 15 wt% chromium, 0.5 wt% silicon, 0.5 wt% manganese, 1 wt% molybdenum, 0.05 wt% nitrogen, 0.05 wt% titanium and residual iron and other impurities Main bodies were prepared. The shape of the ax bodies was substantially the same as in FIG. 1. The ax bodies were 40 cm wide and 25 cm high. The average thickness of the axes was 1 cm, and the average thickness of the axes was 1 mm. The ax bodies were placed in an annealing furnace and heated for 3 hours. The ax bodies were removed from the annealing furnace and measured by a non-contact infrared thermometer, and the average temperature was 800 deg. 800 L of water at room temperature was added to the tank and only the ax blades were quenched for different times. The ax main body was again taken out of the water and tempered at room temperature for different times, and then quenched again for different times for the entire ax blade. The ax body was again taken out of water and tempered again for different times at room temperature. Finally, the ax body was completely immersed in water and cooled.

Experimental Example 1

After primary quenching for 0.5 seconds, primary tempering was performed for 1.5 seconds. And second quenching for 2 seconds and then second tempering for 2.5 seconds. Thereafter, the ax main body was completely immersed in water and cooled. The time was accurately measured using a stopwatch.

Experimental Example 2

After primary quenching for 0.5 seconds, the first tempering was performed for 2 seconds. And second quenching for 2 seconds and then secondary tempering for 3 seconds. The remaining experimental conditions were the same as in Experimental Example 1 described above.

Experimental Example 3

After first quenching for 1 second, the first tempering was performed for 2 seconds. After quenching for 2.5 seconds for 2 seconds, the second tempering was performed for 3 seconds. The remaining experimental conditions were the same as in Experimental Example 1 described above.

Experimental Example 4

After first quenching for 2 seconds, the first tempering was performed for 2.5 seconds. After quenching for 2.5 seconds for 2 seconds, the second tempering was performed for 3 seconds. The remaining experimental conditions were the same as in Experimental Example 1 described above.

Experimental Example 5

After first quenching for 2 seconds, the first tempering was performed for 3 seconds. And second quenching for 3 seconds and then second tempering for 4 seconds. The remaining experimental conditions were the same as in Experimental Example 1 described above.

Experimental Example 6

After first quenching for 2 seconds, the first tempering was performed for 3.5 seconds. After quenching for 2 seconds for 2 seconds, secondary tempering was performed for 4.5 seconds. The remaining experimental conditions were the same as in Experimental Example 1 described above.

Experimental Example 7

After first quenching for 2 seconds, the first tempering was performed for 3.5 seconds. Then, the second quench for 3.5 seconds and then the second tempering for 4.5 seconds. The remaining experimental conditions were the same as in Experimental Example 1 described above.

Experimental Example 8

After first quenching for 2 seconds, the first tempering was performed for 4 seconds. After quenching for 2 seconds for 4 seconds, a second tempering was performed for 5 seconds. The remaining experimental conditions were the same as in Experimental Example 1 described above.

Rockwell hardness (HRC) of the axes obtained through the above experimental examples was measured. That is, Rockwell hardness was measured by pressing a conical diamond having a vertex angle of 120 ° and a tip radius of 0.2 mm on a flat polished ax blade.

Experiment result

The results of analyzing Rockwell hardness of the ax bodies manufactured according to Experimental Examples 1 to 8 were shown in Table 1 below.

Experimental Example First quenching
Time in seconds First tempering
Time in seconds Second quenching
Time in seconds Second tempering
Time in seconds Rockwell hardness
(HRC) Experimental Example 1 0.5 1.5 2 2.5 47 Experimental Example 2 0.5 2 2 3 50 Experimental Example 3 One 2 2.5 3 56 Experimental Example 4 2 2.5 2.5 3 65 Experimental Example 5 2 3 3 4 64 Experimental Example 6 2 3.5 3 4.5 58 Experimental Example 7 2 3.5 3.5 4.5 53 Experimental Example 8 2 4 4 5 51

As a result of the above experiments, generally excellent Rockwell hardness and polishing performance were obtained in the ax bodies of Experimental Examples 1 to 8. In particular, it was evaluated that the Rockwell hardness of the ax bodies of Experimental Examples 4 and 5 exceeded 800 Hv. As a result, it was confirmed that the Rockwell hardness of the ax body was changed according to the quenching time and tempering time, and it was found that it is desirable to appropriately adjust the quenching time and tempering time.

Although the present invention has been described above, it will be readily understood by those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the claims set out below.

10, 14. Ax Body
15. Weldment
20, 24. Handrail Pipe
22. Rubber cover
30. Closure
40. Emergency rope
50. Oxygen concentration meter
501. Housing
503. Handle
80. Robot Hand
90. Countertop
95. Refrigerants
100, 200, 300, 400. Ax
101, 141.The Ax Blade
103, 143. Ax
103a. Pickaxe
105a, 105b, 105c, 105. Spanner groove
107. Square Wrench Groove

Claims (5)

0.5 wt% to 2.5w% C, 10wt% to 20wt% Cr, greater than 0 and less than 1wt% Si, greater than 0 and less than 1wt% Mn, greater than 0 and 3wt% Providing an ax body comprising less than or equal to Mo, greater than 0 and less than or equal to 0.1 wt%, greater than or equal to 0 and less than or equal to 0.1 wt% Ti, residual iron and other impurities,
Heating the ax body to 750 ° C. to 800 ° C.,
Immersing only a portion of the ax blade in a coolant to first quench for a first predetermined time;
Removing the ax body from the coolant and performing primary tempering treatment for a second predetermined time by thermal conduction of the ax lamp having a temperature of 350 ° C to 400 ° C,
Immersing the entire ax blade in the coolant for secondary quenching for a third predetermined time;
Removing the ax body from the coolant and performing secondary tempering treatment for a fourth predetermined time by residual heat of the ax lamp having a temperature of 350 ° C to 450 ° C, and
Cooling the ax body by dipping the coolant
Manufacturing method of the ax comprising a. In claim 1,
The first predetermined time in the first quenching step is 1 second to 2 seconds,
In the step of performing the first tempering, the second preset time is 2 seconds to 3 seconds,
In the second quenching step, the third preset time is 2 seconds to 3 seconds,
The fourth predetermined time in the step of performing the second tempering is a method of producing an ax 3 seconds to 4 seconds. In claim 1,
Providing the ax body,
Providing a steel sheet, and
The steel sheet is folded, pressed and cut by overlapping a plurality of times.
Manufacturing method of the ax comprising a. An ax manufactured by the method according to claim 1,
A handle pipe welded to the ax body and connected;
Opening and closing stopper coupled to one end of the handle pipe
More,
An ax with a rope or oxygen concentration meter inserted into the handle pipe. An ax manufactured by the method according to claim 1,
Further comprising a handle pipe welded and connected to the ax body,
A plurality of spanner grooves are formed on an upper side of the axe, and a square wrench groove larger than each of the plurality of spanner grooves is provided below the ax body opposite the plurality of spanner grooves with the handle pipe therebetween. Formed axe.

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