阅读说明：本技术 一种锤上自由锻大截面船用连杆锻造工艺及其锻造工具 (Hammer free forging large-section marine connecting rod forging process and forging tool thereof ) 是由 孙常奋 袁志强 许久海 安宏宇 于 2019-10-29 设计创作，主要内容包括：本发明公开了一种锤上自由锻船用连杆锻造工艺及其锻造工具,其中工艺包括以下步骤：A、将连杆置于锻锤与砧座之间,将砧块置于连杆的上平面中心；B、锻锤向下打击砧块,砧块向下压入连杆的上平面的有效深度为h；C、将砧块向上取出,再将砧块在连杆的上平面上沿中心向四周移位,锻锤向下打击砧块,砧块向下压入连杆的上平面的有效深度为h,直至整个上平面都压下相同的有效深度h；D、将连杆沿轴线180°翻身,使连杆的下平面朝上,砧块置于连杆的下平面中心,锻锤向下打击砧块,采用与上平面相同的锻造方式,直至整个下平面都压下相同的有效深度h。本发明公开的锻造工艺简单巧妙,自中心向四周边缘进行锻压,提高了锻压有效深度,提高了锻造质量。(The invention discloses a forging process and a forging tool for a connecting rod for a hammer free forging ship, wherein the process comprises the following steps: A. placing a connecting rod between the forging hammer and the anvil block, and placing the anvil block in the center of the upper plane of the connecting rod; B. the forging hammer downwards strikes the anvil block, and the effective depth of the anvil block downwards pressed into the upper plane of the connecting rod is h; C. taking out the anvil block upwards, then displacing the anvil block on the upper plane of the connecting rod along the center to the periphery, downwards striking the anvil block by a forging hammer, and pressing the anvil block downwards into the upper plane of the connecting rod by an effective depth h until the whole upper plane is pressed by the same effective depth h; D. the connecting rod is turned over 180 degrees along the axis, the lower plane of the connecting rod faces upwards, the anvil block is arranged at the center of the lower plane of the connecting rod, the forging hammer downwards strikes the anvil block, and the forging mode same as that of the upper plane is adopted until the whole lower plane is pressed down by the same effective depth h. The forging process disclosed by the invention is simple and ingenious, and the forging is carried out from the center to the peripheral edge, so that the effective forging depth is improved, and the forging quality is improved.)

1. A forging process of a connecting rod for a hammer free forging ship is applied to thinning crystal grains inside a connecting rod for a large-section ship, and is characterized by comprising the following steps:

A. placing a connecting rod (3) between a forging hammer (5) and an anvil block (4), and placing the anvil block at the center of an upper plane (31) of the connecting rod (3);

B. the forging hammer (5) downwards strikes the anvil block, and the effective depth of the anvil block downwards pressed into the upper plane (31) of the connecting rod (3) is h;

C. the anvil block is taken out upwards, then the anvil block is displaced on the upper plane (31) of the connecting rod along the center to the periphery, the forging hammer (5) downwards strikes the anvil block, and the effective depth of the anvil block downwards pressed into the upper plane (31) of the connecting rod (3) is h until the whole upper plane (31) is pressed down to the same effective depth h;

D. the connecting rod (3) is turned over 180 degrees along the axis, the lower plane of the connecting rod (3) faces upwards, the anvil block is arranged at the center of the lower plane of the connecting rod, the forging hammer (5) downwards strikes the anvil block, and the forging mode same as that of the upper plane (31) is adopted until the whole lower plane is pressed down by the same effective depth h.

2. The forging process of the marine connecting rod for the hammer free forging according to claim 1, wherein the effective depth H in the steps B, C and D is not less than 20% of the height H of the connecting rod.

3. The connecting rod forging process for a hammer free forging boat according to claim 1 or 2, wherein the anvil block is a flat anvil or a V-shaped anvil.

4. The forging process of a marine connecting rod for hammer free forging according to claim 1 or 2, wherein the forging temperature of the forging process of the marine connecting rod for hammer free forging is within the finish forging temperature range.

5. The forging process of the marine connecting rod for the free hammer forging according to claim 1 or 2, wherein the forging process of the marine connecting rod for the free hammer forging is suitable for free forging of a large-section forging by a hydraulic machine.

6. The forging process of the connecting rod for the hammer free forging ship according to claim 1 or 2, wherein the forging process of the connecting rod for the hammer free forging ship is suitable for refining grains of large-section carbon steel, alloy steel and stainless steel materials.

7. A forging tool of a marine connecting rod for hammer free forging, which is applied to the forging process of the marine connecting rod for hammer free forging according to any one of claims 1 to 6, and is characterized by comprising a forging hammer (5), an anvil block and an anvil block (4), wherein when in use, the connecting rod (3) is arranged between the forging hammer (5) and the anvil block (4), the anvil block is arranged on the upper plane (31) or the lower plane of the connecting rod (3), and the anvil block is displaced from the center to the periphery; the anvil block comprises a base (1) and a boss (2) protruding out of the surface of the base (1), wherein the boss (2) comprises a first protruding portion (21) and a second protruding portion (22), and the first protruding portion (21) and the second protruding portion (22) form a V shape.

8. The forging tool of marine connecting rod for hammer free forging of claim 7, wherein the first protrusion (21) has a first inclined surface (211) and a second inclined surface (212), the bottom of the first inclined surface (211) is connected to the upper surface (12) of the base, the bottom of the second inclined surface (212) is connected to the upper surface (12) of the base, the top of the first inclined surface (211) is joined to the top of the second inclined surface (212) at a first joining line (213); the second bulge (22) is provided with a third inclined surface (221) and a fourth inclined surface (222), the bottom of the third inclined surface (221) is connected with the upper surface (12) of the base, the bottom of the fourth inclined surface (222) is connected with the upper surface (12) of the base, the top of the third inclined surface (221) is connected with the top of the fourth inclined surface (222), and the joint is a second connecting line (223); the second inclined surface (212) is jointed with the fourth inclined surface (222), the joint is a third connecting line (230), the first inclined surface (211) is jointed with the third inclined surface (221), and the joint is a fourth connecting line (231).

9. The connecting rod forging tool for the hammer forge vessel, as recited in claim 8, wherein a left side portion of said first inclined surface (211) is joined to a left surface (13) of the base at a fifth joint line (110), a front side portion of said first inclined surface (211) is joined to a front surface (11) of the base at a sixth joint line (111); the front side part of the second inclined surface (212) is jointed with the front surface (11) of the base, and the joint is a seventh connecting line (112); the front part of the fourth inclined surface (222) is jointed with the front surface (11) of the base, the joint is an eighth connecting line (113), the front side part of the third inclined surface (221) is jointed with the front surface (11) of the base, the joint is a ninth connecting line (114), the right side part of the third inclined surface (221) is jointed with the right surface (15) of the base, and the joint is a tenth connecting line (115).

10. The connecting rod forging tool for the hammer forge boat according to claim 8, wherein the angle between the first inclined surface (211) and the second inclined surface (212) is in the range of 145 ° to 170 °; the included angle between the third inclined surface (221) and the fourth inclined surface (222) ranges from 145 degrees to 170 degrees; the height of the boss (2) is 10-50 mm.

Technical Field

The invention relates to the field of forging, in particular to a forging process of a connecting rod for a hammer free forging ship and a forging tool thereof.

Background

Key parts such as connecting rods of marine diesel engines and the like are in high-strength reciprocating motion for a long time, alternating stress is applied to the inside of the parts, and the requirement of products on the internal quality of forgings is high. The connecting rod of the diesel engine for the free forging ship, because the hammering energy of the forging hammer is limited, when increasing the local deflection with the anvil block, begin to deform downwards from the edge of upper plane of the connecting rod, please refer to fig. 1, connecting rod 3 is placed between forging hammer 5 and anvil block 4 of free forging, the anvil block is placed on the edge of upper plane of the connecting rod of large cross section, the forging hammer 5 strikes the anvil block downwards, the anvil block is pressed into the upper plane of the connecting rod by a certain depth d downwards, the depth d of pressing is shallow, is 10% of the height H of the cross section, extend from the edge to the plane undeformed region after pressing is finished, until the whole upper plane presses the same depth.

Because the local rolling reduction of the anvil block is shallow, and the deformation mode is expanded from the edge to the whole upper plane, the crystal grains in the large-section connecting rod are difficult to refine, so that the crystal grains in the whole section are not uniform, the fatigue resistance of the product under the alternating stress is reduced, and the ultrasonic flaw detection of the product is not qualified.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a forging process and a forging tool for a connecting rod for a hammer free forging ship, which are applied to thinning crystal grains in a connecting rod for a large-section ship, have simple and ingenious forging process and can effectively solve the technical problems in the background technology.

The purpose of the invention is realized by adopting the following technical scheme:

a forging process of a connecting rod for a hammered free forging ship comprises the following steps:

A. placing a connecting rod between the forging hammer and the anvil block, and placing the anvil block in the center of the upper plane of the connecting rod;

B. the forging hammer downwards strikes the anvil block, and the effective depth of the anvil block downwards pressed into the upper plane of the connecting rod is h;

C. taking out the anvil block upwards, then displacing the anvil block on the upper plane of the connecting rod along the center to the periphery, downwards striking the anvil block by a forging hammer, and pressing the anvil block downwards into the upper plane of the connecting rod by an effective depth h until the whole upper plane is pressed by the same effective depth h;

D. the connecting rod is turned over 180 degrees along the axis, the lower plane of the connecting rod faces upwards, the anvil block is arranged at the center of the lower plane of the connecting rod, the forging hammer downwards strikes the anvil block, and the forging mode same as that of the upper plane is adopted until the whole lower plane is pressed down by the same effective depth h.

By adopting the technical scheme, the forging mode of shifting from the center to the periphery is combined with the characteristic that the temperature of the central position of the plane on the large section of the connecting rod is higher than that of the edge position, the central position is used as a reference, the central position is easy to press down, the deformation can be increased by applying the same forging hammer pressure, and in addition, the central position of the surface of the connecting rod is positioned, so that the connecting rod is stressed uniformly and deforms uniformly when being forged for the first time, and the refining of internal crystal grains is facilitated. In the traditional mode of expanding from the edge to the whole plane, when the connecting rod is forged and pressed for the first time, because the connecting rod is positioned at the edge, the stress of the whole connecting rod plane is uneven and the deformation is irregular, and when the same forging hammer pressure is applied, the deformation is small, and the edge position is taken as a reference, the same plane needs to be repeatedly forged and pressed for multiple times to reach the same effective depth, so that the process is complex, and the production efficiency is low. By adopting the scheme, the initial pressing-down ingenious position, the effective depth h and the deformation mode of the anvil block can effectively refine internal crystal grains when the large-section marine connecting rod is freely forged on a hammer, the production efficiency is improved, the internal and external crystal grains of the whole section of the connecting rod are uniform, the fatigue resistance of a product under the alternating stress is improved, and the ultrasonic flaw detection requirement of the product is met.

As a further improvement of the invention, the effective depth H in the steps B, C and D is more than or equal to 20 percent of the height H of the connecting rod. By adopting the technical scheme, the height H of the connecting rod is the height between the upper plane and the lower plane of the large-section of the connecting rod in the initial state, the effective depth H in each step is more than or equal to 20 percent of the height H of the connecting rod, the optimal maximization of the effective depth can be achieved under the condition that the same forging hammer pressure as that in the prior art is applied, and the forging quality and efficiency are improved. The upper plane and the lower plane are pressed into the effective depth, so that the grain refinement degree in the connecting rod is effectively improved.

As a further improvement of the invention, the anvil block is a flat anvil or a V-shaped anvil. By adopting the technical scheme, the anvil block can select the flat anvil or the V-shaped anvil according to the actual requirement, and the process can solve the problems in the background technology.

As a further improvement of the invention, the forging temperature of the forging process of the on-hammer free forging marine connecting rod is in a finish forging temperature range. By adopting the technical scheme, the forging temperature of each step is in the finish forging temperature range, the finish forging temperature is related to the forged material, the finish forging temperature of different materials is different, so that forging and pressing are performed in the finish forging temperature range, different finish forging temperatures can be selected according to actual materials, and the forging quality is improved.

As a further improvement of the invention, the connecting rod forging process for the hammer free forging boat is suitable for freely forging the large-section forge piece by using a hydraulic press. By adopting the technical scheme, the forging die is suitable for free forging of large-section forgings by a hydraulic press, meets the requirements of production requirements, and is favorable for popularization and application.

As a further improvement of the invention, the forging process of the connecting rod for the hammer free forging ship is suitable for refining grains of large-section carbon steel, alloy steel and stainless steel materials. By adopting the technical scheme, different materials can be subjected to grain refinement by adopting the process, and the application range is wide.

When the connecting rod forging tool is used, the connecting rod is arranged between the forging hammer and the anvil block, the anvil block is arranged on the upper plane or the lower plane of the connecting rod, and the anvil block is shifted from the center to the periphery; the anvil block comprises a base and a boss protruding out of the surface of the base, the boss comprises a first protruding portion and a second protruding portion, and the first protruding portion and the second protruding portion form a V shape. By adopting the technical scheme, the boss protrudes out of the surface of the base, when the connecting rod forging device is used, the surface with the boss is aligned to the connecting rod, the forging hammer downwards strikes the base, and the boss downwards acts on the connecting rod to enable the connecting rod to deform in the height direction, so that grains in the connecting rod of the marine diesel engine can be effectively refined, and the internal quality of the connecting rod with the large section can be improved by freely forging. First bulge and second bulge constitute a V style of calligraphy, and the cross section of boss is the V style of calligraphy promptly, and base and boss constitute the forging instrument of a single V style of calligraphy hammering block for the boss atress is even at forging in-process, is unlikely to lateral shifting, is favorable to improving forging quality and efficiency. Of course, in other schemes adapted to the above process, a flat anvil may be adopted, but the scheme of adopting such a V-shaped anvil is the preferred scheme.

As a further improvement of the present invention, the first protrusion has a first inclined surface and a second inclined surface, the bottom of the first inclined surface is connected to the upper surface of the base, the bottom of the second inclined surface is connected to the upper surface of the base, the top of the first inclined surface is joined to the top of the second inclined surface, and the joint is a first connecting line; the second bulge is provided with a third inclined surface and a fourth inclined surface, the bottom of the third inclined surface is connected with the upper surface of the base, the bottom of the fourth inclined surface is connected with the upper surface of the base, the top of the third inclined surface is connected with the top of the fourth inclined surface, and a second connecting line is arranged at the joint; the second inclined surface is jointed with the fourth inclined surface, the joint is a third connecting line, the first inclined surface is jointed with the third inclined surface, and the joint is a fourth connecting line. Through adopting above-mentioned technical scheme, the respective longitudinal section of first bulge and second bulge is triangle-shaped, and the top is sharper, is favorable to carrying out high-efficient forging and pressing to the connecting rod. When the forging and pressing device is used, the upper surface of the base faces downwards, namely, the lug boss needs to be used for contacting the upper plane of the connecting rod, and the forging and pressing effect is improved.

As a further improvement of the present invention, the left side portion of the first inclined surface is joined to the left surface of the base at a fifth connecting line, the front side portion of the first inclined surface is joined to the front surface of the base at a sixth connecting line; the front side part of the second inclined surface is jointed with the front surface of the base, and a seventh connecting line is arranged at the joint; the front part of the fourth inclined surface is jointed with the front surface of the base, the joint is an eighth connecting line, the front side part of the third inclined surface is jointed with the front surface of the base, the joint is a ninth connecting line, the right side part of the third inclined surface is jointed with the right surface of the base, and the joint is a tenth connecting line. By adopting the technical scheme, the joints of the lug bosses and the side surfaces of the base are irregular, the heights are staggered, uneven surfaces are formed, the area of the effective forging and pressing part is increased, and the forging effect is improved.

As a further improvement of the invention, the included angle between the first inclined surface and the second inclined surface ranges from 145 degrees to 170 degrees; the included angle range of the third inclined surface and the fourth inclined surface is 145-170 degrees; the height of the boss is 10 mm-50 mm. Through adopting above-mentioned technical scheme, adopt this contained angle scope and do not adopt other scopes, be favorable to improving on the one hand and forge the effect, on the other hand, because of the obtuse angle, also can not cause the damage to connecting rod or boss itself to a certain extent, improved life. The protruding height range of the boss is convenient for the shape and size design of the boss, and is also beneficial to forming high-efficiency and high-quality processing on the connecting rod, thereby improving the forging effect.

Compared with the prior art, the invention has the beneficial effects that: the forging and pressing mode of shifting from the center to the periphery is adopted, the central position is used as a reference, the same forging hammer pressure is applied, the deformation can be increased, the stress of the connecting rod during the initial forging and pressing can not be uniform, the deformation is uniform, the refining of internal crystal grains is facilitated, the production efficiency is improved, the internal crystal grains and the external crystal grains of the whole section of the connecting rod are uniform, the fatigue resistance of a product under the alternating stress is improved, and the ultrasonic flaw detection requirement of the product is met.

Drawings

FIG. 1 is a schematic diagram of a solution according to the background art;

FIG. 2 is a schematic diagram of a process and tools for forging a connecting rod for a hammer forging boat;

FIG. 3 is a schematic view of an anvil configuration of a marine ram forging tool for hammer forging according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the structure of FIG. 3 after the addition of labels;

FIG. 5 is a schematic view of another angle of the drill block of FIG. 3 according to the present invention;

FIG. 6 is a front side elevational view of the drill block of FIG. 3 in accordance with the present invention;

FIG. 7 is a top view of the buttons of FIG. 3 according to the present invention;

fig. 8 is a schematic sectional view taken along line a-a in fig. 7.

In the figure: 1. a base; 2. a boss; 3. a connecting rod; 4. an anvil block; 5. forging a hammer; 11. a front surface; 12. an upper surface; 13. a left surface; 14. a rear surface; 15. a right surface; 21. a first projecting portion; 31. an upper plane; 110. a fifth connecting line; 111. a sixth connecting line; 112. a seventh connecting line; 113. an eighth connecting line; 114. a ninth connecting line; 115. a tenth connecting line; 116. a fifth connecting line; 121. a first connecting line; 122. a third connecting line; 123. a second connecting line; 124. a fourth connecting line; 211. a first inclined surface; 212. a second inclined surface; 213. a first connecting line; 22. a second projection; 221. a third inclined surface; 222. a fourth inclined surface; 223. a second connecting line; 230. a third connecting line; 231. and a fourth connecting line.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention.

It should be noted that: the above, lower, left, right, front and rear are only for clarity and do not represent the only limitations to the scope of the present application.

Example 1

Referring to fig. 2, the forging process of the marine connecting rod free-forged on the hammer is applied to thinning the internal crystal grains of the marine connecting rod with the large section, and comprises the following steps:

A. placing the connecting rod 3 between the hammer 5 and the anvil 4, and placing the anvil in the center of the upper plane 31 of the connecting rod 3;

B. the forging hammer 5 downwards strikes an anvil block, and the effective depth of the anvil block downwards pressed into the upper plane 31 of the connecting rod 3 is h;

C. taking out the anvil block upwards, then displacing the anvil block on the upper plane 31 of the connecting rod along the center to the periphery, and downwards striking the anvil block by the forging hammer 5, wherein the effective depth of the anvil block downwards pressed into the upper plane 31 of the connecting rod 3 is h until the whole upper plane 31 is pressed down by the same effective depth h;

D. the connecting rod 3 is turned over by 180 degrees along the axis, the lower plane of the connecting rod 3 faces upwards, the anvil block is arranged at the center of the lower plane of the connecting rod, the forging hammer 5 downwards strikes the anvil block, and the same forging mode as the upper plane 31 is adopted until the whole lower plane is pressed down by the same effective depth h. The effective depth H in the steps B, C and D is more than or equal to 20 percent of the height H of the connecting rod. In the scheme, the forging and pressing mode of shifting from the center to the periphery is combined with the characteristic that the temperature of the central position of the plane on the large section of the connecting rod is higher than that of the edge position, the central position is used as a reference, the central position is easy to press down, the deformation can be increased by applying the same forging hammer pressure, and in addition, the central position of the surface of the connecting rod is positioned, so that the connecting rod is stressed uniformly when being forged and pressed for the first time, the deformation is uniform, and the refining of internal crystal grains is facilitated. The original pressing-down ingenious position, the effective depth h and the deformation mode of the anvil block in the scheme are adopted, so that internal crystal grains can be effectively refined when the large-section marine connecting rod is freely forged on a hammer, and the production efficiency is improved.

The anvil block is a flat anvil or a V-shaped anvil, which can be adapted to the above process. The forging temperature of the forging process of the connecting rod for the hammer free forging ship is in the range of the finish forging temperature. The forging process of the connecting rod for the hammer free forging boat is suitable for freely forging large-section forgings by using a hydraulic press. The forging process of the connecting rod for the hammer free forging ship is suitable for refining grains of large-section carbon steel, alloy steel and stainless steel materials. The forging method has the advantages that the material selection range of the forging object is wide, and the popularization and the application are convenient.

Example 2

A forging tool for a marine connecting rod for free forging on a hammer is applied to the forging process for the marine connecting rod for free forging on a hammer in embodiment 1, and comprises a hammer 5, an anvil block and an anvil block 4, when in use, a connecting rod 3 is arranged between the hammer 5 and the anvil block 4, the anvil block is arranged on the upper plane 31 or the lower plane of the connecting rod 3, and the anvil block is shifted from the center to the periphery (the orientation is shown in figure 2 for reference).

Referring to fig. 3-6, reference is made to up, down, left, right, front, and back in the orientation shown in fig. 4. The anvil block comprises a base 1 and a boss 2 protruding from an upper surface 12 of the base 1. The boss 2 includes a first projecting portion 21 and a second projecting portion 22, and the first projecting portion 21 and the second projecting portion 22 form a V-shape. In this embodiment, the first protrusion 21 and the second protrusion 22 are both one, i.e. they form a single V shape, so the structure is simple and smart, and the service life is prolonged. In other embodiments, there may be more than one first protrusion 21 and/or second protrusion 22 to form a continuous boss, thereby improving forging quality.

Referring to fig. 4 and 5, the longitudinal section of the boss is triangular, and specifically, the first protrusion 21 has a first inclined surface 211 and a second inclined surface 212, the bottom of the first inclined surface 211 is connected to the upper surface 12 of the base at a connection point of the first connecting line 121, the bottom of the second inclined surface 212 is connected to the upper surface 12 of the base at a connection point of the second connecting line 123. The top of the first inclined surface 211 is jointed with the top of the second inclined surface 212, and the joint is a first connecting line 213; the second protrusion 22 has a third inclined surface 221 and a fourth inclined surface 222, wherein the bottom of the third inclined surface 221 is connected to the upper surface 12 of the base at a connection line three 122. The bottom of the fourth inclined surface 222 is connected to the upper surface 12 of the base, and the connection line is four 124. The top of the third inclined surface 221 is jointed with the top of the fourth inclined surface 222, and the joint is a second connecting line 223; the second inclined surface 212 is joined to the fourth inclined surface 222 at a joint of the third connecting line 230, and the first inclined surface 211 is joined to the third inclined surface 221 at a joint of the fourth connecting line 231. The boss comprises two convex parts, and the longitudinal section of each convex part is triangular, so that the connecting rod can be conveniently forged and formed.

The left side of the first inclined surface 211 is jointed with the left surface 13 of the base at a joint of a fifth connecting line 110, the front side of the first inclined surface 211 is jointed with the front surface 11 of the base at a joint of a sixth connecting line 111; the front side of the second inclined surface 212 is joined to the front surface 11 of the base at a seventh connecting line 112; the front portion of the fourth inclined surface 222 is joined to the front surface 11 of the base at a joint of the eighth connecting line 113, the front side portion of the third inclined surface 221 is joined to the front surface 11 of the base at a joint of the ninth connecting line 114, the right side portion of the third inclined surface 221 is joined to the right surface 15 of the base at a joint of the tenth connecting line 115. The base upper surface 12 is joined to the base right surface 15 at a junction line five 116.

Referring to fig. 7 and 8, an included angle B between the first inclined surface 211 and the second inclined surface 212 ranges from 145 ° to 170 °; the included angle between the third inclined surface 221 and the fourth inclined surface 222 ranges from 145 degrees to 170 degrees. The included angle between the first convex part 21 and the second convex part 22 is 15-170 DEG

The base 1 has a rectangular or square shape. The base has a front surface 11, a rear surface 14, an upper surface 12, a left surface 13, and a right surface 15. The boss 2 is integrally formed on the upper surface 12, that is, the boss 2 is disposed on the long and wide plane of the base 1. Referring to fig. 4, the height D of the projection of the boss 2 is 10mm to 50 mm. It is advantageous to form an effective hammer for the connecting rod 3.

When the connecting rod forging device is used, referring to fig. 2, the connecting rod 3 is placed on the anvil block 4, one surface of the boss 2 of the anvil block is in contact with the surface center of the connecting rod 3, namely the base 1 in the anvil block is located above the boss 2, the boss 2 is located below the boss, the surface of the base 1 is beaten by the forging hammer, and the connecting rod is forged in a high-efficiency and high-quality mode by the aid of the first protruding portion and the second protruding portion on the boss 2, namely the boss 2 downwards enables the connecting rod 3 to generate large-range plastic deformation in the height direction, grains in the connecting rod of the marine diesel engine are effectively refined, and internal quality of the connecting.

In other embodiments, a forging tool for a marine connecting rod for hammer free forging includes a base 1 and a boss 2 protruding from an upper surface 12 of the base 1. The cross section of the boss 2 is arc-shaped or wavy, and the longitudinal section of the boss 2 is arc-shaped, trapezoid or rectangular. The usage method in this embodiment is as described in embodiment 1, and is not described again.

In summary, the forging process and the forging tool can solve the technical problems in the background technology, improve the forging quality and are beneficial to wide popularization and application. Of course, the scheme of the application can be suitable for free forging of refined internal crystal grains of other large-section forgings. It is understood that they are also within the scope of the present application.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.