CN110640117A

CN110640117A - Bimetal composite pouring bent pipe for concrete conveying and manufacturing method

Info

Publication number: CN110640117A
Application number: CN201911029782.0A
Authority: CN
Inventors: 帅德发
Original assignee: Gucheng Dacheng Machinery Co Ltd
Current assignee: Gucheng Dacheng Machinery Co Ltd
Priority date: 2019-10-28
Filing date: 2019-10-28
Publication date: 2020-01-03

Abstract

The invention relates to the technical field of concrete conveying pipe manufacturing, in particular to a bimetal composite casting elbow pipe for concrete conveying and a manufacturing method thereof. The invention has simple structure, can thoroughly prevent the inner and outer bent pipes from separating and falling off, and reduces the use failure rate; the adopted manufacturing method is simple and practical, the production difficulty is greatly reduced, and the production efficiency is improved; and because the inner container is cast by adopting a high-strength wear-resistant corrosion-resistant material, the quality requirement can be met under the condition that the whole elbow is thinner, so that the weight of the elbow is reduced, the weight of equipment using the elbow is finally reduced, and the safety and the stability of the equipment are improved.

Description

Bimetal composite pouring bent pipe for concrete conveying and manufacturing method

Technical Field

The invention relates to the technical field of concrete conveying pipe manufacturing, in particular to a bimetal composite pouring bent pipe for concrete conveying and a manufacturing method thereof.

Background

In recent years, with the vigorous development of the building industry, high-pressure concrete conveying pump trucks are continuously updated, the height and distance of concrete pumped by the arm support are also continuously increased, and higher requirements are provided for the performance and the service life of an arm support conveying pipeline, particularly a shock-bearing and wear-resistant elbow part. In addition, the high-speed conveyed materials generate a large centrifugal force when the bent pipes are conveyed by the arm support, so that the impact abrasion and corrosion of the high-speed materials to the outer sides of the conveying bent pipes are aggravated, and the materials become the weakest ring in the conveying pipeline. That is, the elbow pipe for conveying concrete needs the performances of wear resistance, high pressure resistance, corrosion resistance, high strength, difficult damage and the like, and the existing hinge elbow pipe, reducing elbow pipe, climbing pipe, taper pipe, lengthening elbow pipe and the like are usually formed by combining an inner pipe with the performances and an outer pipe which is sleeved with the inner pipe and has toughness.

As shown in figure 1, the prior common elbow for concrete conveying comprises a shell made of common carbon steel and one or more sections of wear-resistant lining pipes sleeved in the shell, wherein two ends of the elbow adopt a clamping head welded with the shell and a blocking pipe matched with the clamping head in a wedge shape, and then the shell is perforated with slurry to fill a gap between the shell and the lining pipe. In actual use, the installation and positioning of the lining pipe are often damaged by feeding of the gaps of the multiple sections of lining pipes, so that the lining pipes move, the service life of the bent pipe is shortened, and in addition, the welding line between the chuck and the shell is often subjected to desoldering, so that the bent pipe is damaged, and the production is influenced.

In addition, the prior art also adopts a double-layer metal casting structure, namely the inner and outer layers of bent pipes are cast simultaneously, or one of the bent pipes is cooled to a certain temperature and then the other bent pipe is cast, and the two bent pipes need to be manufactured into a mould with a connected cavity structure, so that the structure process is complex, and the defects of slag inclusion, air holes and the like are easily generated at the metal position between layers. As for the casting of the outer pipe first and then the inner pipe by the centrifugal method, it is not suitable for the manufacture of the bent pipe, and the wall thickness of the formed inner pipe cannot be locally deviated.

Disclosure of Invention

The invention aims to provide a bimetal composite casting elbow pipe for concrete conveying and a manufacturing method thereof aiming at the defects of the prior art. Therefore, the bimetal composite bent pipe which meets the working condition requirement of concrete conveying, has the inner container which can not fall off and is easy to produce and manufacture is obtained.

The technical scheme adopted by the invention for solving the technical problems is as follows: a bimetal composite pouring elbow pipe for concrete conveying comprises an inner container cast by a corrosion-resistant and wear-resistant material and a shell coated on the inner container through casting mold secondary pouring, wherein the wall thickness of the inner container is gradually thickened from the inner arc to the outer arc of the elbow pipe along the circumferential direction and from the two ends to the middle of the elbow pipe along the axial direction, biting ribs convenient for occlusion of the shell are arranged on the surface of the inner container, and inner buckle sealing rings for blocking the end face of the inner container are arranged at the two ends of the shell.

Furthermore, the biting ribs are net-shaped raised lines.

Furthermore, groove-shaped clamping rings are arranged at the two ends of the shell, and the side faces of the clamping rings are inclined planes.

Further, the thickness of the inner container is 5-10 mm.

Further, the liner material is ZNS150+ Q. The material is a novel material, and the brand specification thereof is as follows: ZNS represents cast corrosion-resistant alloy, 1 represents solid solution strengthening iron-based alloy, 5 represents Ni, Cr, Mo, Cu, V, Al and RE alloy, 0 represents temporary unnumbered, + represents composite, and Q represents surface layer high-quality carbon steel.

Further, the inner container material comprises the following components in percentage by mass:

C＝2.3％-3.2％，S≤0.04％，P≤0.04％，Cr＝20％-24％，Si＝0.4％-1.2％,Mn＝0.5％-1.0％,Mo＝1.0％-1.4％,Ni＝1.0％-1.5％,Cu＝0.5％-1.0％,V＝0.5％-1.1％,Al＝0.1％-0.3％,B＝0.005％-0.006％,RE≤0.3％。

further, the housing material is Q345.

Further, the manufacturing method of the bimetal composite casting elbow for concrete conveying is characterized by comprising the following steps:

SP 1: casting the inner container of the conveying bent pipe with molten steel of the brand ZNS150+ Q, specifically controlling the tapping temperature of the molten steel to be 1560 ℃, the casting temperature to be 1500 ℃, the casting speed to be 6 seconds, and cooling and cleaning to form a standard inner container object.

SP 2: and putting a standard inner container real object into the prepared shell mould shell to replace the inner core, and closing the box.

SP 3: pouring the molten steel of Q345 brand into a mold shell of a closed box, controlling the tapping temperature of the molten steel at 1610 ℃, controlling the pouring temperature at 1560 ℃, pouring at the speed of 10 seconds, covering the covering agent within 5 seconds after the pouring, and pouring again within 10 seconds.

SP 4: the casting mould can be opened when naturally cooled to 30 ℃.

SP 5: and cleaning and polishing the product blank molded by secondary casting, and then carrying out heat treatment.

Further, the heat treatment process is quenching and tempering, namely, the temperature is raised to 1084 ℃ at an acceleration of 40 ℃ per hour, the temperature is preserved for 4 hours, then the furnace temperature is naturally reduced to 960 ℃, the furnace is taken out of the furnace and air-cooled to 350 ℃, the temperature is preserved for 1.5 hours, and then the furnace is taken out of the furnace and air-cooled continuously.

Furthermore, the compression resistance of the inner container after heat treatment is 25MPa, and the hardness is HRC 66.

The invention has the beneficial effects that: a bimetal composite cast elbow pipe for conveying concrete is composed of antiwear and anticorrosion internal container and the bimetal elbow pipe consisting of fused casing, and features that the antiwear and anticorrosion internal container is cast first, the cooled internal container is used as core to cast the casing, and the high-temp metal is used to fuse the internal and external bimetal elbow pipes. The invention has scientific structure, can thoroughly prevent the inner and outer bent pipes from separating and falling off, and reduces the use failure rate; the adopted manufacturing method is simple and practical, the production difficulty is greatly reduced, and the production efficiency is improved; and because the inner container is cast by adopting a high-strength wear-resistant corrosion-resistant material, the quality requirement can be met under the condition that the whole elbow is thinner, so that the weight of the elbow is reduced, the weight of equipment using the elbow is finally reduced, and the safety and the stability of the equipment are improved.

Drawings

FIG. 1 is a schematic cross-sectional view of a prior art elbow;

FIG. 2 is a schematic cross-sectional view of a bimetallic composite cast elbow for concrete delivery of the present invention.

Description of reference numerals:

1-inner container, 11-biting rib, 2-outer shell, 21-interface ring, 22-snap ring.

Detailed Description

The present invention will be described in further detail with reference to the following drawings and specific examples, which are not intended to limit the scope of the invention.

As shown in fig. 2, the bimetal composite pouring elbow for concrete conveying of this embodiment includes an inner container 1 and a housing 2 that is cast and coated on the inner container 1 by a casting mold, the wall thickness of the inner container 1 gradually increases from the inner arc to the outer arc of the elbow along the circumferential direction and from the two ends to the middle of the elbow along the axial direction, the surface of the inner container 1 is provided with a biting rib 11 that is convenient for the housing 2 to be occluded, and the two ends of the housing 2 are provided with interface rings 21 that are internally buckled and block the end surface of the inner container 1. The biting ribs 11 are a plurality of raised rings axially distributed along the outer wall of the inner container 1, or raised lines distributed on the outer wall of the inner container 1 in a criss-cross manner.

The elbow is characterized in that the inner container 1 is cast by adopting a high-strength wear-resistant corrosion-resistant material ZNS150+ Q, then the outer shell 2 is poured on the outer layer of the inner container 1 by taking the inner container 1 as a core, the outer shell 2 adopts Q345 molten steel, and the outer shell 2 is subjected to secondary pouring hot melting through the reticular convex lines on the outer wall of the inner container 1, so that the outer shell 2 is more tightly fused and occluded with the inner container 1, the two are basically fused into a whole, and the separation and falling off in use can be avoided. Under the condition of meeting the equal quality requirement, the elbow pipe can be made thinner, in actual use, the thickness of the thickest position of the integral elbow pipe is 15mm, the thinnest position is 6.5mm, and other materials are not required to be filled between the inner elbow pipe and the outer elbow pipe, so that the weight of a product is reduced, the self weight of a pump truck is further reduced, the weight of an arm support of the pump truck is reduced, and the safety and the stability of the pump truck are improved.

Because the hardness of the inner container 1 is too high and is not beneficial to machining, the joint ring 21 is arranged at the end face of the two ends of the bent pipe, the joint ring 21 is formed by casting the shell 2 integrally and covers the end face of the inner container 1 inside, the thickness of the joint ring 21 after machining is 1mm, and when the tight fit of the connecting position of the bent pipe is ensured, the gap between the two sections of conveying pipes after the joint ring 21 is worn is reduced as much as possible. The both ends of shell 2 are provided with the fluted type snap ring 22 that is used for the clamp joint when the return bend is connected, and the fluted type side of snap ring 22 is the inclined plane, promptly the cross-section of snap ring 22 is the trapezoidal that the big end of mouth is little, and the clamp card gets tighter like this, and two sections return bends are laminated tighter.

The bimetal composite casting bent pipe of the invention is compared with the prior similar products as follows:

the table shows that the bimetal composite pouring elbow pipe has higher hardness and better use effect, effectively reduces the use and replacement frequency, thereby reducing cost and improving efficiency, basically has no fault in use, and prevents the damage to personnel and equipment.

The bimetal composite casting bent pipe is formed by two-step casting, and the manufacturing method comprises the following steps:

SP 4: the casting mould can be opened when naturally cooled to 30 ℃.

It can be known that the two-time casting of the invention is to cast the inner container 1 first, and then cast the outer shell 2 by using the cooled inner container 1 as a core, so that the difficulty of manufacturing a mold is reduced, and the mutual influence of two metals during fusion and solidification is also reduced, namely, the defects of slag inclusion, air holes and the like are not formed between the inner container 1 and the outer shell 2. The secondary casting of SP3 is to make a replacement for molten metal in order to prevent the formation of shrinkage cavities when the molten metal solidifies.

And fifthly, cleaning and polishing the product blank molded by secondary casting, and then carrying out heat treatment, wherein the specific process comprises quenching and tempering, namely, the whole cast bimetal composite bent pipe is put into an intermediate frequency furnace, the temperature is raised to 1084 ℃ at the accelerated speed of 40 ℃ per hour, the temperature is kept for 4 hours, then the furnace temperature is naturally reduced to 960 ℃, the product is taken out of the furnace and air-cooled to 350 ℃, the temperature is kept for 1.5 hours, and then the product is taken out of the furnace and air-cooled.

The product after heat treatment can reach the following mechanical properties:

and sixthly, processing the interface ring 21 and performing other treatments. The snap ring 22 may be cast or machined.

The inner container 1 is cast by adopting a novel material ZNS150+ Q, and the components of the existing high-chromium iron-based material are improved by comprehensively considering the action of various elements in metal smelting and the working condition requirement applicable to the bimetal composite casting elbow pipe, and the method specifically comprises the following steps:

as can be seen from the table, the content of conventional element components is reduced by the novel material ZNS150+ Q, and V, Al, B and RE (rare earth) are increased, so that as-cast metal forms net-shaped carbide, the toughness and the heat strength of the material are improved, the material has higher oxidation resistance, the stability of the main structure of the material, namely the super-cooled austenite is improved, and higher hardenability is obtained. RE can perform modification treatment on molten steel during solidification to obtain a fine-grained cast structure. Therefore, the tissue structure and the mechanical property of the material are comprehensively improved, for example, after the material obtained by casting is subjected to heat treatment, the hardness of BTMCr26 is HRC58, the hardness of 25Cr is HRC56, and the hardness of the newly-created material ZNS150+ Q is HRC66, so that the material meets the requirement of the corrosivity of the concrete C60 grade, and the metallographic structure of the body is denser and has higher toughness and strength.

The invention can be used for concrete conveying equipment, and can also be used for other equipment which needs wear resistance, corrosion resistance and high pressure, such as conveying equipment of coal dust, slurry and the like.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A bimetal composite pouring return bend for concrete feeding, its characterized in that: including adopting anticorrosive wear-resisting material casting's inner bag (1) and through casting mould pouring cladding shell (2) of inner bag (1), the wall thickness of inner bag (1) is all thickened gradually from the inner arc to the outer arc of return bend, along the both ends of axial from the return bend to the centre along circumference, the surface of inner bag (1) is provided with and is convenient for sting muscle (11) of shell (2) interlock, the both ends of shell (2) are provided with interior knot and block connect face ring (21) of inner bag (1) terminal surface.

2. The bimetallic composite cast elbow for concrete delivery according to claim 1, characterized in that: the biting ribs (11) are net-shaped raised lines.

3. The bimetallic composite cast elbow for concrete delivery according to claim 1, characterized in that: groove-shaped snap rings (22) are arranged at two ends of the shell (2).

4. The bimetallic composite cast elbow for concrete delivery according to claim 1, characterized in that: the thickness of the inner container (1) is 5-10 mm.

5. The bimetallic composite cast elbow for concrete delivery according to claim 1, characterized in that: the inner container (1) is made of ZNS150+ Q.

6. The bimetallic composite cast elbow for concrete delivery according to claim 5, characterized in that: the inner container (1) is made of the following materials in percentage by mass: 2.3 to 3.2 percent of C, less than or equal to 0.04 percent of S, 20 to 24 percent of Cr, 0.4 to 1.2 percent of Si, 0.5 to 1.0 percent of Mn, 1.0 to 1.4 percent of Mo, 1.0 to 1.5 percent of Ni, less than or equal to 0.04 percent of P, 0.5 to 1.0 percent of Cu, 0.5 to 1.1 percent of V, 0.1 to 0.3 percent of Al, 0.005 to 0.006 percent of B, and less than or equal to 0.3 percent of RE.

7. The bimetallic composite cast elbow for concrete delivery according to claim 1, characterized in that: the material of the shell (2) is Q345.

8. A method of manufacturing the bimetallic composite cast elbow for concrete delivery of claim 1, characterized by: the method comprises the following steps:

SP 1: firstly, casting the liner (1) by molten steel with the brand number ZNS150+ Q, specifically, controlling the tapping temperature of the molten steel to be 1560 ℃, the casting temperature to be 1500 ℃ and the casting speed to be 6 seconds, and cooling and cleaning to form a standard real object of the liner (1);

SP 2: putting a standard real object of the inner container (1) into the prepared outer shell mould shell to replace an inner core, and closing the box;

SP 3: pouring the molten steel of Q345 brand into a mold shell of a closed box, controlling the tapping temperature of the molten steel at 1610 ℃, controlling the pouring temperature at 1560 ℃, pouring at a speed of 10 seconds, covering the covering agent within 5 seconds after the pouring, and pouring again within 10 seconds;

SP 4: opening the casting mould when the casting mould is naturally cooled to 30 ℃;

9. The method of manufacturing a bimetallic composite cast elbow for concrete delivery according to claim 8, characterized in that: the heat treatment process is quenching and tempering, namely, the temperature is increased to 1084 ℃ at an acceleration speed of 40 ℃ per hour, the temperature is preserved for 4 hours, then the furnace temperature is naturally reduced to 960 ℃, the furnace is taken out and air-cooled to 350 ℃, the temperature is preserved for 1.5 hours, and then the furnace is taken out and air-cooled continuously.