阅读说明：本技术 定向钻杆的加工工艺 (Processing technology of directional drill rod ) 是由 蒋开勇 张凌 李和祥 史春宝 蒲剑 罗华 张俞 潘小叶 赵志强 田乐意 杜渔舟 于 2019-09-29 设计创作，主要内容包括：本发明公开了一种定向钻杆的加工方法,包括下料、毛坯件机加工及热处理、焊接、钻杆热处理及机加工、表面处理,所述下料包括公接头下料、钢管下料和母接头下料；所述毛坯件机加工及热处理包括接头锻造、粗车、调质及半精车,钢管机加工及校直；所述焊接为摩擦焊；所述钻杆热处理及机加工包括焊缝回火、车焊疤和数车螺纹；所述表面处理包括磷化及喷漆。本发明简化了定向钻杆加工工艺流程、加工方便、钻杆使用寿命长、安全可靠,该加工方法无需镦粗设备、无整体调质、校直、探伤、整体加工两端螺纹等工序,且特殊设备投入少、钻杆加工快捷、产品质量稳定可靠,解决了钻杆加工周期长、生产成本高、质量问题频发等疑难技术缺陷。(The invention discloses a method for processing a directional drill rod, which comprises the steps of blanking, blank piece machining and heat treatment, welding, drill rod heat treatment and machining and surface treatment, wherein the blanking comprises male joint blanking, steel pipe blanking and female joint blanking; the machining and heat treatment of the blank piece comprises joint forging, rough turning, tempering and semi-finish turning, and machining and straightening of a steel pipe; the welding is friction welding; the heat treatment and machining of the drill rod comprise welding seam tempering, welding scar turning and thread turning; the surface treatment comprises phosphating and painting. The invention simplifies the processing process flow of the directional drill rod, has convenient processing, long service life of the drill rod, safety and reliability, does not need upsetting equipment, has no procedures of integral tempering, straightening, flaw detection, integral processing of threads at two ends and the like, has less investment of special equipment, quick processing of the drill rod and stable and reliable product quality, and solves the difficult technical defects of long processing period of the drill rod, high production cost, frequent quality problems and the like.)

1. A processing method of a directional drill rod is characterized by comprising the following steps: the method comprises the steps of blanking, blank piece machining and heat treatment, welding, drill rod heat treatment and machining and surface treatment, wherein the blanking comprises male connector blanking, steel pipe blanking and female connector blanking; the machining and heat treatment of the blank piece comprises joint forging, rough turning, tempering and semi-finish turning, and machining and straightening of a steel pipe; the welding is friction welding; the heat treatment and machining of the drill rod comprise welding seam tempering, welding scar turning and thread turning; the surface treatment comprises phosphating and painting.

The method specifically comprises the following steps:

a. blanking:

a1. blanking the male connector, namely blanking the round steel by a sawing machine to reach the process size, and reserving forging, turning and friction welding allowance;

a2. blanking the steel pipe, namely blanking the seamless quenched and tempered steel pipe by a sawing machine to reach the process size, and reserving turning and friction welding allowance;

a3. blanking the female joint, namely blanking the round steel by a sawing machine to reach the process size, and reserving forging, turning and friction welding allowance;

b. machining and heat treatment of blank pieces:

b1. the male connector is sequentially processed according to the design size: forging, namely precisely forging the blanking of the a1 into a specified size and shape by using a corresponding die; rough turning, namely turning the forged blank piece according to the requirements of a rough turning drawing and meeting the process design requirements; quenching and tempering, wherein the material grade of the a1 blanking is certain alloy structural steel, quenching is carried out firstly, then tempering is carried out, the quenching temperature is 820-880 ℃, the medium is oil quenching, and the tempering temperature is 580-620 ℃; semi-finish turning, namely finishing the external dimension processing of the male connector by using a lathe, reserving finish turning allowance and reserving allowance space for numerical control processing of male thread; counting, namely finish-turning the external thread of the male connector by adopting a numerical control lathe and meeting the design requirement of a drawing;

b2. the steel pipe is sequentially processed according to the design size: the end faces are turned, the two end faces of the steel pipe are polished and leveled by using a lathe, and the designed surface roughness and verticality requirements are met; straightening, namely straightening by a hydraulic press, and performing point type straightening by a press machine to meet the requirement of designed straightness;

b3. sequentially carrying out the following steps of (1) sequentially carrying out the female joint according to the design size: forging, namely precisely forging the blanking of the a3 into a specified size and shape by using a corresponding die; rough turning, namely turning the forged blank piece according to the design requirements of a rough turning drawing and meeting the process design requirements; quenching and tempering, wherein the material grade of the a3 blanking is certain alloy structural steel, quenching is carried out firstly, then tempering is carried out, the quenching temperature is 820-880 ℃, the medium is oil quenching, and the tempering temperature is 580-620 ℃; semi-finish turning, namely finishing the external dimension processing of the female joint by using a lathe, reserving finish turning allowance and reserving allowance space for numerical control processing of female buckle threads;

c. welding: welding the male joint, the steel pipe and the female joint into a whole by using a C63A friction welding machine, wherein the welding temperature of a welding seam is 1070-1085 ℃, the shortening of a single-head welding seam is 10mm, and the straightness tolerance of a drill rod is less than or equal to 0.50 mm/m;

d. integral heat treatment and machining of the drill rod:

d1. tempering the whole drill rod, wherein the tempering temperature is between 600 ℃ and 620 ℃, the direct current voltage is 420 +/-20V, the heating time is 35s, and the heating length is 20 mm;

d2. counting, machining the total length and the internal thread of the drill rod, turning the end face of the drill rod to ensure the total length size, machining the internal thread by using a customized thread forming blade, and finally machining a matching hole and a retainer ring groove to reach the size;

e. surface treatment:

e1. phosphorization, in which a drill rod is firstly degreased and derusted and then is wholly immersed into an acidic dilute aqueous solution consisting of phosphating solution (the pH value is 1.8-2.2, the relative density of the solution is 1.08-1.30) and containing Fe (H2PO4)2, Mn (H2PO4)2 and Zn (H2PO4) 2) for carrying out medium-temperature (50-75 ℃) phosphorization treatment on threads;

e2. spraying paint, namely performing paint spraying treatment on the part of the outer surface of the drill rod needing rust prevention;

f. and (5) after the processing is finished, warehousing the drill rod outer pipe for loading.

2. The method of claim 1, wherein the method further comprises: and c, carrying out hardness detection and metallographic analysis on the forged blank in the step b1 after quenching and tempering, wherein adopted detection equipment is a Rockwell hardness meter and a metallographic analyzer.

3. The method of claim 1, wherein the method further comprises: and c, carrying out hardness detection and metallographic analysis on the forged blank in the step b3 after quenching and tempering, wherein adopted detection equipment is a Rockwell hardness meter and a metallographic analyzer.

4. The method of claim 1, wherein the method further comprises: in the step d1, the drill rod after the tempering treatment is subjected to finish turning to remove internal and external scars and burrs left by welding.

5. The method of claim 1, wherein the method further comprises: detecting the welded drill rod, wherein the detection method comprises the following steps: carrying out torsion resistance detection on the welded phi 70 directional drill rod by using torque detection equipment, wherein the required damage torque is more than 12000 N.m; simultaneously, performing a tensile test on the welded drill rod sample, wherein the tensile yield strength of the sample is required to be more than or equal to 850 MPa; and (4) performing impact test, wherein the average value AKv2 of the test sample is required to be more than or equal to 16.3J, and the drill rod is required to perform ultrasonic nondestructive inspection.

6. The method of claim 1, wherein the method further comprises: after the internal thread of the drill rod in the step d2 is processed, the taper, the thread pitch, the tight distance and the thread form angle of the drill rod are detected by using a taper plug gauge and a thread plug gauge, and the design requirements are met: the average error of the thread pitch is +/-0.025 mm, and the tolerance value of the full-length error of the thread is not more than 0.1 mm.

Technical Field

The invention relates to the technical field of mining drilling tool machining, in particular to a method for machining a directional drill rod.

Background

The quality of the directional drill rod component is directly dependent on the processing technology of the directional drill rod, and the quality of the directional drill rod component is one of the most important drilling tools in coal mine drilling equipment. A key component of the directional drill rod assembly, namely the directional drill rod, is purchased all the time, after the steel pipe is blanked, the heading machine is adopted to perform induction heating on the steel pipe for 2-3 times, and then upsetting, flaw detection, integral tempering, flaw detection again, integral straightening and thread counting are performed to complete the processing of the directional drill rod.

The upsetting time is long, the heating time is difficult to master, the heating temperature is inconvenient to control, impurities are increased in the heating process, the upsetting quality of the directional drill rod is directly influenced, particularly the impurities are increased, so that the pipe body is easy to deform and crack in the upsetting process, the defects of uneven wall thickness, eccentricity, wrinkles and the like sometimes occur, the upsetting quality is difficult to guarantee, and the return phenomenon often occurs. The integral quenching and tempering is carried out by using a well-type quenching furnace, the hardness of the drill rod and the processing schedule can be directly influenced if the heat treatment medium is selected improperly, and the integral quenching and tempering quality is not suitable to be controlled.

The original process route has the following defects:

(1) directional drill rods are purchased externally, the processing period is long, and the management difficulty is high.

(2) The production cost is high.

(3) The processing efficiency is low.

(4) The product quality is not stable.

Therefore, in order to solve the above problems, a new directional drill rod processing method is needed, which simplifies the processing flow, is convenient to process, has long service life of the drill rod, is safe and reliable, does not need upsetting equipment, and does not have the procedures of integral tempering, straightening, flaw detection and integral processing of threads at two ends, more importantly, has less investment of special equipment, is convenient to process the drill rod, has higher reliability, and solves the difficult technical defects of long processing period of the directional drill rod, high production cost, frequent quality problems and the like.

Disclosure of Invention

In view of the above, the invention aims to overcome the defects in the prior art, provides a novel directional drill rod processing method, and provides a friction welding type directional drill rod processing technology which is convenient to process, long in service life of a drill rod, safe and reliable. The processing method does not need upsetting equipment, does not have the procedures of integral tempering, straightening, flaw detection and integral processing of threads at two ends, has less investment of special equipment, convenient processing of the drill rod and higher reliability, solves the technical defects of long processing period of the drill rod, high production cost, frequent quality problems and the like, and has the following advantages: the method reduces the investment of the existing external processing upsetting and heating equipment, lightens the labor intensity of workers, improves the forming efficiency of the pipe body, can achieve the design intensity by one-time friction welding, shortens the processing period and has simple and convenient process route. The allowance of the total length of the multi-lathe machining is reserved, so that reliable guarantee is provided for the subsequent multi-lathe female joint and the total length of the directional drill rod is guaranteed; the tempering process is simple and feasible, the welding internal stress of the friction welding seam can be eliminated by setting reasonable tempering parameters, and the product quality is stabilized; the inner and outer welding scars are finely turned to remove welding rings generated by friction welding, so that the follow-up normal assembly is guaranteed, and the attractiveness of the drill rod is improved; the number-turning female joint process ensures the requirement on the total length of the drill rod, processes the inner hole, the retainer ring groove and the thread, ensures the requirements on the precision, the coaxiality and the roughness of the thread, provides reliable guarantee for the subsequent hydrostatic test, and reduces the production cost and the product quality accident rate; and in the phosphating process, medium-temperature or high-temperature phosphating is adopted for phosphating the threads of the drill rod, so that the phenomena of thread abrasion, burrs, snap-in and the like in use are avoided, and the integral service life of the directional drill rod is prolonged.

The processing method of the directional drill rod comprises the steps of blanking, blank piece machining and heat treatment, welding, drill rod heat treatment and machining and surface treatment, wherein the blanking comprises male joint blanking, steel pipe blanking and female joint blanking; the machining and heat treatment of the blank piece comprises joint forging, rough turning, tempering and semi-finish turning, and machining and straightening of a steel pipe; the welding is friction welding; the heat treatment and machining of the drill rod comprise welding seam tempering, welding scar turning and thread turning; the surface treatment comprises phosphating and painting.

The method specifically comprises the following steps:

b. blanking:

a1. blanking the male connector, namely blanking the round steel by a sawing machine to reach the process design size, and reserving forging, turning and friction welding allowance;

a2. blanking the steel pipe, namely blanking the seamless quenched and tempered steel pipe by a sawing machine to reach the process design size, and reserving turning and friction welding allowance;

a3. blanking the female joint, namely blanking the round steel by a sawing machine to reach the process design size, and reserving forging, turning and friction welding allowance;

b. machining and heat treatment of blank pieces:

b1. the male connector is sequentially processed according to the design size: forging, namely precisely forging the blanking of the a1 into a specified design shape by using a corresponding die; rough turning, turning the forged blank piece according to the design requirements of a rough turning drawing and achieving the design requirements; quenching and tempering, wherein the material grade of the a1 blanking is certain alloy structural steel, quenching is carried out firstly by adopting a pit furnace, then tempering is carried out, the quenching temperature is 820-880 ℃, the medium is oil quenching, and the tempering temperature is 580-620 ℃; semi-finish turning, namely finishing the external dimension processing of the male connector by using a lathe, reserving finish turning allowance and reserving allowance space for numerical control processing of male thread; counting, namely finish-turning the external thread of the male connector by adopting a numerical control lathe and meeting the design requirement of a drawing;

b2. the steel pipe is sequentially processed according to the design size: the end faces are turned, the two end faces of the steel pipe are polished and leveled by using a lathe, and the designed surface roughness and verticality requirements are met; straightening, namely straightening by a hydraulic press, and performing point type straightening by a press machine to meet the requirement of designed straightness;

b3. sequentially carrying out the following steps of (1) sequentially carrying out the female joint according to the design size: forging, namely precisely forging the blanking of the a3 into a specified design shape by using a corresponding die; rough turning, turning the forged blank piece according to the design requirements of a rough turning drawing and achieving the design requirements; quenching and tempering, wherein the material grade of the a3 blanking is certain alloy structural steel, quenching is carried out firstly by adopting a pit furnace, then tempering is carried out, the quenching temperature is 820-880 ℃, the medium is oil quenching, and the tempering temperature is 580-620 ℃; semi-finish turning, namely finishing the external dimension processing of the female joint by using a lathe, reserving finish turning allowance and reserving allowance space for numerical control processing of female buckle threads;

c. welding: welding the male joint, the steel pipe and the female joint into a whole by using a C63A friction welding machine, wherein the welding temperature of a welding seam is 1070-1085 ℃, the shortening of a single-head welding seam is 10mm, and the straightness tolerance of a drill rod is less than or equal to 0.50 mm/m;

d. integral heat treatment and machining of the drill rod:

d1. tempering the whole drill rod, wherein the tempering temperature is between 600 ℃ and 620 ℃, the direct current voltage is 420 +/-20V, the heating time is 35s, and the heating length is 20 mm;

d2. counting, machining the total length and the internal thread of the drill rod, turning the end face of the drill rod to ensure the total length size, machining the internal thread by using a customized thread forming blade, and finally machining a matching hole and a retainer ring groove to reach the size;

e. surface treatment:

e1. phosphorization, in which a drill rod is firstly degreased and derusted and then is wholly immersed into an acidic dilute aqueous solution consisting of phosphating solution (the pH value is 1.8-2.2, the relative density of the solution is 1.08-1.30) and containing Fe (H2PO4)2, Mn (H2PO4)2 and Zn (H2PO4) 2) for carrying out medium-temperature (50-75 ℃) phosphorization treatment on threads;

e2. spraying paint, namely performing paint spraying treatment on the part of the outer surface of the drill rod needing rust prevention;

f. and (5) after the processing is finished, warehousing the drill rod outer pipe for loading.

Further, in the step b1, hardness detection and metallographic analysis are performed on the male connector forging blank after quenching and tempering, and adopted detection equipment is a Rockwell hardness meter and a metallographic analyzer.

Further, in the step b3, hardness detection and metallographic analysis are performed on the female joint forging blank after quenching and tempering, and adopted detection equipment is a Rockwell hardness meter and a metallographic analyzer.

Further, in the step d1, the drill rod after the tempering treatment is subjected to finish turning to remove internal and external scars and burrs left by welding.

Further, the detection method for the welded drill rod comprises the following steps: carrying out torsion resistance detection on the welded phi 70 directional drill rod by using torque detection equipment, wherein the required damage torque is more than 12000 N.m; simultaneously, performing a tensile test on the welded drill rod, wherein the tensile yield strength of a sample is required to be more than or equal to 850 MPa; and (3) impact test, wherein the average value AKv2 of the sample is required to be more than or equal to 16.3J, and ultrasonic nondestructive inspection is required.

Further, after the internal thread of the drill rod in the step d2 is processed, the taper, the thread pitch, the tight distance and the thread form angle of the drill rod are detected by using a taper plug gauge and a thread plug gauge, and the design requirements are met: the average error of the thread pitch is +/-0.025 mm, and the tolerance value of the full-length error of the thread is not more than 0.1 mm.

The invention has the beneficial effects that: compared with the traditional processing method, the processing method of the directional drill rod disclosed by the invention has the following advantages:

1) the process adopts friction welding of the male and female connectors, is simple and feasible compared with an upsetting process, reliably ensures the quality of the connectors, greatly enhances the flexibility and the adaptability, simplifies the processing process, reduces the requirements of processing equipment, and avoids quality defects of uneven upsetting wall thickness, wrinkles, eccentricity, slag inclusion and the like.

2) The thread at two ends is turned by a numerical control lathe in the process, the average error of the thread pitch of the thread is +/-0.025 mm and is less than the tolerance value requirement, the error in the whole length of the thread is also less than the tolerance value by 0.1mm, the tightness distance is easy to control, the precision is high, and the surface roughness of the thread also reaches the national standard.

3) The process adopts the pit furnace as heating equipment in the quenching procedure, has high heating speed, does not have the phenomena of internal cooling, external heating and uneven cooling and heating, effectively controls the increase of heating time and impurities, and greatly improves the efficiency and the quality.

4) For exampleThe overall test result of the comprehensive mechanical property of the friction weld of the outer pipe of the directional drill rod is excellent: the yield strength is more than or equal to 850MPa in a tensile test; in an impact test, the average value AKv2 of the sample is more than or equal to 16.3J; the static torque strength is more than or equal to 12000N.m in a torque test.

5) The screw thread screwing life of the drill rod after the screw thread phosphating treatment is more than or equal to 500 times.

6) The processing period is shortened, and the processing efficiency of the directional drilling rod is improved by more than 40%.

7) The processing cost of the directional drill rod is reduced by over 35 percent.

8) The product quality is improved.

Drawings

The invention is further described below with reference to the following figures and examples:

FIG. 1 is a schematic view of the directional drill rod of the present invention;

fig. 2 is a process flow diagram of fig. 1.

Wherein: 1. a first O-ring seal; 2. a spring connecting seat; 3. a second O-ring seal; 4. a cable connector; 5. an adjustment pad; 6. a support ring; 7. a retainer ring; 8. a third O-ring seal; 9. protecting the core tube; 10. a cable core rod; 11. three-wing support; 12. a spring fixing seat; 13. a spring; 14. a cable connecting seat; 15. directional drill rod

Detailed Description

Fig. 1 is a schematic structural diagram of a directional drill rod of the present invention, and fig. 2 is a process flow diagram of fig. 1, where as shown in the diagram, the processing method of the directional drill rod in the present embodiment includes blanking, blank machining and heat treatment, welding, drill rod weld seam heat treatment and machining, and surface treatment, where the blanking includes male joint blanking, steel pipe blanking, and female joint blanking; the machining and heat treatment of the blank piece comprise forging, turning and hardening and tempering; the welding is friction welding; the heat treatment and machining of the drill rod weld joint comprise tempering and turning; the surface treatment comprises phosphating and paint spraying;

the method specifically comprises the following steps:

c. blanking:

a1. blanking the male connector, namely blanking the round steel to reach the design size through a sawing machine, and reserving forging, turning and friction welding allowance;

a2. blanking the steel pipe, namely blanking the seamless quenched and tempered steel pipe by a sawing machine to reach a design size, reserving turning and friction welding allowance, and detecting chemical and mechanical properties of the blanked steel pipe;

a3. blanking the female joint, namely blanking the round steel to reach the design size through a sawing machine, and reserving forging, turning and friction welding allowance;

b. machining and heat treatment of blank pieces:

b1. the male connector is sequentially processed according to the design size: forging, namely precisely forging the blanking of the a1 into a specified design shape by using a corresponding die, so that the organization structure of the male joint of the drill rod is more precise, and the comprehensive mechanical property is better; rough turning, turning the forged blank piece according to the design requirements of a rough turning drawing and achieving the design requirements; quenching and tempering, wherein the material grade of the a1 blanking is certain alloy structural steel, quenching and tempering treatment are carried out firstly by adopting a pit furnace, the quenching temperature is 820-880 ℃, the medium is oil quenching, the tempering temperature is 580-620 ℃, the hardness and the metallographic structure of the male joint are improved through heat treatment, the quenching is carried out by adopting the pit furnace for heating, the heating is fast, the phenomena of internal cooling, external heating and uneven cooling and heating can not occur, the heating time and the increase of impurities are effectively controlled, the processing efficiency is improved, the integral mechanical property of the drill rod is improved, and the drill rod has stronger hardness and good plasticity and toughness; semi-finish turning, namely finishing the external dimension processing of the male connector by using a lathe, reserving finish turning allowance, and reserving space for numerical control processing of the male thread so as to facilitate the processing of the next process; counting, finish-turning the external thread of the male connector by adopting a numerical control lathe to meet the design requirement of a drawing, improving the processing precision by adopting the numerical control lathe, processing the thread by using a customized thread forming blade, and detecting the taper, the thread pitch, the tight distance and the thread form angle by using a taper ring gauge and a thread ring gauge to meet the high-precision processing requirement;

b2. the steel pipe is sequentially processed according to the design size: the end faces are turned, the two end faces of the steel pipe are polished and leveled by using a lathe, and the designed surface roughness and verticality requirements are met; straightening, namely straightening by a hydraulic press, performing point-type straightening by using a press to meet the requirement of the designed straightness, and straightening by the hydraulic press because the steel pipe is a quenched and tempered pipe and has poor straightness. Point type straightening is carried out by adopting a press machine, so that the straightness requirement of friction welding is ensured, the friction welding dislocation is reduced, and the straightness and coaxiality requirements of the drill rod are improved;

b3. sequentially carrying out the following steps of (1) sequentially carrying out the female joint according to the design size: forging, namely precisely forging the blanking of the a3 into a specified design shape by using a corresponding die, so that the organization structure of the drill rod female joint is more precise, and the comprehensive mechanical property is better; rough turning, turning the forged blank piece according to the design requirements of a rough turning drawing and achieving the design requirements; quenching and tempering, wherein the material grade of the a3 blanking is certain alloy structural steel, quenching and tempering treatment are carried out firstly by adopting a pit furnace, the quenching temperature is 820-880 ℃, the medium is oil quenching, the tempering temperature is 580-620 ℃, the hardness and the metallographic structure of the female joint are improved through heat treatment, the quenching can be carried out by adopting the pit furnace, the heating speed is high, the phenomena of internal cooling, external heating and uneven cooling and heating can not occur, the heating time and the increase of impurities are effectively controlled, the processing efficiency is improved, the integral mechanical property of the drill rod is improved, and the drill rod has stronger hardness and good plasticity and toughness; semi-finish turning, namely finishing the external dimension processing of the female joint by using a lathe, reserving finish turning allowance and reserving allowance space for numerical control processing of female buckle threads;

c. welding: the male joint, the steel pipe and the female joint are welded into a whole by using a C63A friction welding machine, the welding temperature of a welding seam is 1070-1085 ℃, the shortening of the single-head welding seam is 10mm, the straightness tolerance of a drill rod is less than or equal to 0.50mm/m, and the process is convenient and quick and has higher efficiency and welding strength;

d. integral heat treatment and machining of the drill rod:

d1. tempering the welding seam of the drill rod at the temperature of 600-620 ℃, with direct current voltage of 420 +/-20V, heating time of 35s and heating length of 20mm, wherein the welding inner stress can be generated after the drill rod is welded, the inner stress of the welding seam of the drill rod is eliminated through tempering, the balance of the inner stress of the drill rod is maintained, the martensite distributed in a strip shape is eliminated, and a uniform tempered sorbite structure is obtained, so that the drill rod has good toughness and plasticity, and the stability of the metallographic structure of the welding seam of the drill rod is ensured;

d2. counting, processing the total length of the drill rod and the internal thread, processing the internal thread by using a customized thread forming blade, detecting the taper, the thread pitch, the tight distance and the thread form angle by using a taper plug gauge and a thread plug gauge, and finally processing a matching hole and a retainer ring groove to reach the size;

e. surface treatment:

e1. phosphorization, in which a drill rod is firstly degreased and derusted and then is wholly immersed into an acidic dilute aqueous solution consisting of a phosphorization solution (Fe (H2PO4)2, Mn (H2PO4)2 and Zn (H2PO4)2, the pH value is 1.8-2.2, the relative density of the solution is 1.08-1.30) for carrying out medium-temperature (50 ℃ -75 ℃) phosphorization treatment on threads, so that the phenomena of thread abrasion, burr and snap-in of the drill rod are avoided, and the service life, strength and abrasion resistance of the whole threads are also greatly improved;

e2. spraying paint, namely spraying paint on the part of the outer surface of the drill rod needing rust prevention, so that the overall aesthetic degree, the decoration and the rust prevention capability of the drill rod are improved, and the pipe body is prevented from rusting;

f. and (5) after the processing is finished, warehousing the drill rod outer pipe for loading.

In this embodiment, hardness detection and metallographic analysis are performed on the forged male connector blank in step b1 after quenching and tempering, adopted detection equipment is a rockwell hardness tester and a metallographic analyzer, hardness detection using rockwell hardness tester is simple to operate, measurement is rapid, direct reading can be performed from a dial indicator or an optical projection screen or a display screen, and the use method is simple and is not repeated herein; the metallographic analyzer in the prior art is in a full-automatic mode, and is divided into cold embedding, hot embedding and the most critical metallographic automatic analysis software from full-automatic cutting, full-automatic grinding, full-automatic polishing and automatic embedding of metallographic pretreatment, so that errors caused by human factors are greatly reduced, the standard degree accuracy of metallographic sample preparation is improved, the metallographic analyzer serves as the prior art, and the detailed description is omitted.

In this embodiment, hardness detection and metallographic analysis are performed on the forged female joint blank in step b3 after quenching and tempering, adopted detection equipment is a rockwell hardness tester and a metallographic analyzer, hardness detection using rockwell hardness tester is simple to operate, measurement is rapid, direct reading can be performed from a dial indicator or an optical projection screen or a display screen, and the use method is simple and is not repeated herein; the metallographic analyzer in the prior art is in a full-automatic mode, and is divided into cold embedding, hot embedding and the most critical metallographic automatic analysis software from full-automatic cutting, full-automatic grinding, full-automatic polishing and automatic embedding of metallographic pretreatment, so that errors caused by human factors are greatly reduced, the standard degree accuracy of metallographic sample preparation is improved, the metallographic analyzer serves as the prior art, and the detailed description is omitted.

In this embodiment, in the step d1, the drill rod after the tempering treatment is subjected to finish turning to remove internal and external scars and burrs left by welding, and the internal and external scars of the drill rod are removed by finish turning, so as to assemble internal parts of the drill rod and improve the appearance of the outer pipe of the drill rod.

In this embodiment, the detection method for detecting the welded drill rod includes: carrying out torsion resistance detection on the welded phi 70 directional drill rod by using torque detection equipment, wherein the required damage torque is more than 12000 N.m; meanwhile, a tensile test is carried out on the welded weld joint sample, and the tensile yield strength is required to be more than or equal to 850 MPa; and (3) impact test, wherein the average value AKv2 of the sample is required to be more than or equal to 16.3J, and ultrasonic nondestructive inspection is required.

In this embodiment, after the internal thread of the drill rod in step d2 is processed, the taper, the thread pitch, the tight distance, and the profile angle are detected by using a taper plug gauge and a thread plug gauge, and the design requirements are met: the average error of the thread pitch of the thread is +/-0.025 mm, the tolerance value of the error of the full length of the thread is not more than 0.1mm, the tightness distance is easy to control, the precision is high, and the roughness of the surface of the thread also reaches the national standard.

Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.