阅读说明：本技术 一种小直径深孔的激光熔覆加工方法 (Laser cladding processing method for small-diameter deep hole ) 是由 侯俊明 于 2021-07-29 设计创作，主要内容包括：本发明公开了一种小直径深孔的激光熔覆加工方法,包括以下操作步骤：整理清洁,保持加工件的深孔内壁的干净；预热处理；撤除预热装置开始测距定位；开始施焊,关闭光点器,开启激光灯,同时经过焊机枪头向深孔内壁上喷涂焊粉,通过激光产生的高温将焊粉熔焊在深孔内壁上以此形成熔覆层；进行后热保温处理；去应力处理；无损检测。本发明采用特殊改装过的内孔激光熔覆枪头,能够对中小孔径工件内壁进行熔覆堆焊,采用粉末合金的焊材型式,将粉末通过激光熔覆的方式进行内孔的堆焊,熔覆层与深孔内壁之间形成良好的冶金结合,熔覆层组织致密,热影响区小且稀释率低,熔覆材料具有选择多样性,可根据不同的工程需求设计不同的合金比例。(The invention discloses a laser cladding processing method of a small-diameter deep hole, which comprises the following operation steps: cleaning, namely keeping the inner wall of the deep hole of the workpiece clean; preheating; removing the preheating device to start ranging and positioning; starting welding, closing the spot device, starting a laser lamp, spraying welding powder on the inner wall of the deep hole through a welding machine gun head, and welding the welding powder on the inner wall of the deep hole through high temperature generated by laser to form a cladding layer; carrying out post-heat insulation treatment; stress removal treatment; and (4) carrying out nondestructive testing. The inner hole laser cladding gun head is specially modified, cladding and surfacing can be carried out on the inner wall of a workpiece with a medium and small diameter, powder is subjected to inner hole surfacing in a laser cladding mode by adopting a welding material type of powder alloy, good metallurgical bonding is formed between a cladding layer and the inner wall of a deep hole, the cladding layer is compact in structure, a heat affected zone is small, the dilution rate is low, the cladding material has multiple choices, and different alloy proportions can be designed according to different engineering requirements.)

1. The laser cladding processing method of the small-diameter deep hole is characterized by comprising the following operation steps of:

s1: cleaning, namely keeping the inner wall of the deep hole of the workpiece clean;

s2: preheating, namely extending a heating head of a preheating device into the inner wall of the deep hole, evaporating the cleaning agent remained on the inner wall of the deep hole during cleaning through high temperature generated by the preheating device, and preheating the inner wall of the deep hole to enable the surface temperature of the inner wall to reach 150-200 ℃;

s3: removing the preheating device to start ranging and positioning, attaching a sliding range finder on a gun head of a laser welding machine to the outer surface wall of the deep hole opening, starting a monitoring probe on the gun head of the welding machine, starting a light spot machine, pushing the gun head of the welding machine into the deep hole, identifying the position of a light spot emitted by the light spot machine on a processing mark on the inner wall of the deep hole through a vision technology, recording the reading of the sliding range finder by the laser welding machine at the moment, taking the reading as a depth value of processing welding, and taking an instrument for driving a workpiece to act as an action parameter during subsequent welding;

s4: after S3, the gun head of the laser welding machine is positioned at the end of the welding area, welding is started, the light spot device is closed, the laser lamp is started, meanwhile, welding powder is sprayed on the inner wall of the deep hole through the gun head of the welding machine, and the welding powder is welded on the inner wall of the deep hole through high temperature generated by laser to form a cladding layer;

s5: post heat treatment, namely covering the surface of the cladding layer with a heat preservation material or preserving heat by using a heat preservation furnace after welding;

s6: stress relief treatment, integral postweld heat treatment, wherein the temperature is 638 +/-10 ℃, the heat preservation time is 3 to 6 hours, the temperature rise/reduction speed is less than 100 ℃/h, and furnace air cooling is carried out;

s7: and (4) nondestructive testing, wherein PT detects the welding defect condition of the surface of the cladding layer, and UT detects the internal quality condition of the cladding layer.

2. The laser cladding processing method of the small-diameter deep hole as claimed in claim 1, wherein in the welding process, a numerical control device controls a mechanical arm to drive a processing workpiece to move.

3. The laser cladding processing method of the small-diameter deep hole according to claim 1, wherein a gun head of the welding machine is an elbow, a reflector arranged inside the gun head is used for changing a light path, so that an outlet of the light path points to the inner wall of the deep hole, and an included angle between the changed light path and an original light path is 90-150 degrees.

4. The laser cladding processing method of the small-diameter deep hole as claimed in claim 1, wherein the sliding distance meter is composed of a sliding rheostat and a contact piece, the contact piece is used for contacting with the outer wall of the deep hole, the sliding rheostat is arranged on the outer wall of the head of the welding machine, and the contact piece is arranged on the outer wall of a sliding contact of the sliding rheostat.

5. The laser cladding processing method of the small-diameter deep hole according to claim 1, wherein the monitoring probe is used for shooting in real time and transmitting video data to a display.

6. The laser cladding processing method of the small-diameter deep hole according to claim 1, wherein in step S1, solid dust on the inner wall of the deep hole is removed by using a clean cloth, oil stains on the surface of the inner wall of the deep hole are removed by using a cleaning agent, the cleaning agent in the cleaned hole is removed by using a rust remover, and finally the rust remover in the deep hole is removed by using the clean cloth.

7. The laser cladding processing method of the small-diameter deep hole according to claim 1, wherein when welding is performed in the step S4, the temperature between welding layers is kept less than 300 ℃, the laser power is 3KW to 4KW, a semiconductor device is adopted as a light source, and the powder feeding amount of welding powder is 40 g/min to 70 g/min.

8. The laser cladding processing method of the small-diameter deep hole according to claim 1, wherein before and during welding, a shielding gas is continuously introduced into the deep hole.

9. The laser cladding processing method of the small-diameter deep hole according to any one of claims 1 to 8, wherein the light spot device and the exit of the laser are the same exit, and the light source of the light spot device is a common red light source for indicating the position to which the laser will point after being turned on.

Technical Field

The invention relates to the technical field of laser cladding, in particular to a laser cladding processing method of a small-diameter deep hole.

Background

Laser cladding is also called laser cladding, and is a novel surface modification technology of a laser cladding processing method of a small-diameter deep hole. The method is characterized in that a cladding material is added on the surface of a base material, and the cladding material and a thin layer on the surface of the base material are fused together by utilizing a laser beam with high energy density, so that a cladding layer which is metallurgically bonded with the base layer is formed on the surface of the base layer. Compared with surfacing, spraying, electroplating and vapor deposition, laser cladding has the characteristics of small dilution, compact structure, good combination of a coating and a matrix, more suitable cladding materials, large particle size and content change and the like, so the application prospect of the laser cladding technology is very wide.

In the prior art, only large-diameter pipelines can be cladded by the laser cladding technology of the welding head at the present stage, and for small-diameter pipelines, the laser head is difficult to enter the pipelines due to the spatial limitation of cladding, so that the realization process is complex and the consumption is high.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provides a laser cladding processing method of a small-diameter deep hole.

The invention provides a laser cladding processing method of a small-diameter deep hole, which comprises the following operation steps:

s1: cleaning, namely keeping the inner wall of the deep hole of the workpiece clean;

s2: preheating, namely extending a heating head of a preheating device into the inner wall of the deep hole, evaporating the cleaning agent remained on the inner wall of the deep hole during cleaning through high temperature generated by the preheating device, and preheating the inner wall of the deep hole to enable the surface temperature of the inner wall to reach 150-200 ℃;

s3: removing the preheating device to start ranging and positioning, attaching a sliding range finder on a gun head of a laser welding machine to the outer surface wall of the deep hole opening, starting a monitoring probe on the gun head of the welding machine, starting a light spot machine, pushing the gun head of the welding machine into the deep hole, identifying the position of a light spot emitted by the light spot machine on a processing mark on the inner wall of the deep hole through a vision technology, recording the reading of the sliding range finder by the laser welding machine at the moment, taking the reading as a depth value of processing welding, and taking an instrument for driving a workpiece to act as an action parameter during subsequent welding;

s4: after S3, the gun head of the laser welding machine is positioned at the end of the welding area, welding is started, the light spot device is closed, the laser lamp is started, meanwhile, welding powder is sprayed on the inner wall of the deep hole through the gun head of the welding machine, and the welding powder is welded on the inner wall of the deep hole through high temperature generated by laser to form a cladding layer;

s5: post heat treatment, namely covering the surface of the cladding layer with a heat preservation material or preserving heat by using a heat preservation furnace after welding;

s6: stress relief treatment, integral postweld heat treatment, wherein the temperature is 638 +/-10 ℃, the heat preservation time is 3 to 6 hours, the temperature rise/reduction speed is less than 100 ℃/h, and furnace air cooling is carried out;

s7: and (4) nondestructive testing, wherein PT detects the welding defect condition of the surface of the cladding layer, and UT detects the internal quality condition of the cladding layer.

As a still further scheme of the invention: in the welding process, the mechanical arm is controlled by the numerical control device to drive the machined workpiece to move.

As a still further scheme of the invention: the gun head of the welding machine is an elbow, a reflector arranged in the gun head is used for changing a light path, so that an outlet of the light path points to the inner wall of the deep hole, an included angle between the changed light path and an original light path is 90-150 degrees, and welding is facilitated.

As a still further scheme of the invention: the sliding distance meter is composed of a sliding rheostat and a contact piece, the contact piece is used for contacting the outer wall of the deep hole, the sliding rheostat is arranged on the outer wall of the welding machine gun head, and the contact piece is arranged on the outer wall of a sliding contact of the sliding rheostat.

As a still further scheme of the invention: the monitoring probe is used for shooting in real time and transmitting video data to the display.

As a still further scheme of the invention: in the step S1, the solid dust on the inner wall of the deep hole is removed by using a clean cloth, the oil stain on the surface of the inner wall of the deep hole is removed by using a cleaning agent, the cleaning agent in the deep hole is cleaned, the oxide layer on the surface of the inner wall in the deep hole is removed by using a rust remover, and finally the rust remover in the deep hole is removed by using the clean cloth.

As a still further scheme of the invention: and in the step S4, when welding, the temperature between welding layers is kept to be less than 300 ℃, the laser power is 3KW to 4KW, a light source adopts a semiconductor device, and the powder feeding amount of welding powder is 40 to 70 g/min.

As a still further scheme of the invention: and before and during welding, continuously introducing shielding gas into the deep hole.

As a still further scheme of the invention: the light spot device and the laser have the same outlet, and the light source of the light spot device is a common red light source and is used for indicating the position to which the laser will point after being started.

The beneficial effects of the invention are as follows: the inner wall of a workpiece with a medium and small aperture can be subjected to cladding surfacing by adopting a specially modified inner hole laser cladding gun head, the inner wall of the workpiece with the medium and small aperture can be subjected to cladding surfacing by adopting a welding material type of powder alloy, the powder is subjected to the surfacing by adopting a laser cladding mode, a cladding layer and the inner wall of a deep hole of a processing base body form good metallurgical bonding, the cladding layer has compact tissue, a heat affected zone is small, the dilution rate is low, the cladding material has multiple choices, and different alloy proportions can be designed according to different engineering requirements so as to effectively control the tissue and the performance of the cladding layer in the cladding process; the monitoring probe and the spot light device are matched with each other, so that the welding spot marking position set in advance can be automatically identified through a visual image technology, and welding predictability is realized.

Detailed Description

The following further describes embodiments of the present invention with reference to examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

In the description of this patent, it is to be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the positional or orientational relationships indicated by the documents to facilitate the description of the patent and to simplify the description, but are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be construed as limiting the patent.

In the description of this patent, it is noted that unless otherwise specifically stated or limited, the terms "mounted," "connected," and "disposed" are to be construed broadly and can include, for example, fixedly connected, disposed, detachably connected, disposed, or integrally connected and disposed. The specific meaning of the above terms in this patent may be understood by those of ordinary skill in the art as appropriate.

A laser cladding processing method of a small-diameter deep hole comprises the following operation steps:

s1: cleaning, keeping the inner wall of the deep hole of the workpiece clean, and facilitating the formation of a cladding layer on the inner wall of the deep hole of the workpiece;

s2: preheating, namely extending a heating head of a preheating device into the inner wall of the deep hole, evaporating the cleaning agent remained on the inner wall of the deep hole during cleaning through high temperature generated by the preheating device, and preheating the inner wall of the deep hole to enable the surface temperature of the inner wall to reach 150-200 ℃;

s3: removing the preheating device to start ranging and positioning, attaching a sliding range finder on a gun head of a laser welding machine to the outer surface wall of the deep hole opening, starting a monitoring probe on the gun head of the welding machine, starting a light spot machine, pushing the gun head of the welding machine into the deep hole, identifying that a light spot emitted by the light spot machine is positioned at a processing mark position on the inner wall of the deep hole through a vision technology, recording the reading of the sliding range finder at the moment by the laser welding machine, taking the reading as a depth value of processing welding, and taking an instrument for driving a workpiece to act as an action parameter during subsequent welding;

s4: after S3, the gun head of the laser welder is positioned at the end of the welding area, welding is started, the light spot device is closed, the laser lamp is started, alloy powder (welding powder) is sent into the laser beam from the coaxial powder feeding gun head (welder gun head) through powder feeding gas, and is focused at a position 20mm away from the inner wall of the deep hole of the workpiece to form an alloy molten pool, the workpiece moves according to a certain speed to form a track molten pool, a cladding layer is formed on the surface of the workpiece, and the laser welder is cooled by water cooling in the welding process;

s5: post heat treatment, namely covering the surface of the cladding layer with a heat preservation material or preserving heat by using a heat preservation furnace after welding;

s6: stress relief treatment, integral postweld heat treatment, wherein the temperature is 638 +/-10 ℃, the heat preservation time is 3 to 6 hours, the temperature rise/reduction speed is less than 100 ℃/h, and furnace air cooling is carried out;

s7: nondestructive testing, wherein PT detects the welding defect condition of the surface of the cladding layer, UT detects the internal quality condition of the cladding layer, and welding defects such as air holes, incomplete fusion and cracks.

In the invention, in the welding process, the mechanical arm is controlled by the numerical control device to drive the machined workpiece to move.

According to the invention, the gun head of the welding machine is an elbow, the reflector arranged in the gun head is used for changing the light path, so that the outlet of the light path points to the inner wall of the deep hole, the included angle between the changed light path and the original light path is 90-150 degrees, and the welding is convenient.

According to the invention, the sliding distance meter consists of a sliding rheostat and a contact piece, the contact piece is used for contacting the outer wall of the deep hole, the sliding rheostat is arranged on the outer wall of a welding machine gun head, and the contact piece is arranged on the outer wall of a sliding contact of the sliding rheostat.

In the invention, the monitoring probe is used for shooting in real time and transmitting video data to the display, so that the marking position can be automatically identified through a visual image technology.

In the invention, in step S1, solid dust on the inner wall of the deep hole is removed by using clean cloth, oil stains on the surface of the inner wall of the deep hole are removed by using a cleaning agent, the cleaning agent in the deep hole is cleaned, the rust remover is used for removing an oxide layer on the surface of the inner wall in the deep hole, and finally the rust remover in the deep hole is cleaned by using the clean cloth, so that the formation and the attachment of a cladding layer are facilitated.

In the invention, when welding is carried out in the step S4, the welding interlayer temperature is kept to be less than 300 ℃, the laser power is 3KW to 4KW, a light source adopts a semiconductor device, the powder feeding amount of welding powder is 40 to 70g/min, the light spot range is 10-20mm, the welding working efficiency is 0.65 square meter/h to 1.25 square meter/h, the thickness of a cladding layer is 0.5-3mm, if the welding temperature exceeds the interlayer temperature in the welding process, an alarm is carried out by a set temperature thermometer, the welding powder is alloy powder, one or more of iron-based, nickel-based, cobalt-based, copper-based and composite materials are mixed in any proportion, and different alloy proportions are designed according to different engineering requirements so as to effectively control the organization and performance of the cladding layer in the cladding process.

In the invention, before and during welding, the shielding gas is continuously introduced into the deep hole to avoid the oxidation of a welding point, and the introduced shielding gas can not scatter welding powder.

In the invention, the light spot device and the laser have the same outlet, and the light source of the light spot device is a common red light source and is used for indicating the position to which the laser will point after being started, so that the functions of observation indication and prediction are achieved, and the starting position of welding is known before the laser is started.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.