CN102294545A - Laser penetration welding seam formation control method for Hass alloy conductive roller - Google Patents

Abstract

A Hass alloy conduction roller laser penetration welding seam forming control method, using Hass alloy steel plate for cylinder rounding, the edge of the plate of the butt joint before the rounding is processed into a bevel, and the butt joint after the rounding forms an I-shaped slope The rounded cylinder is assembled on the fixture to complete the joint assembly; the laser welding seam forming control adopts the air-cooled-copper liner to control the back of the weld to form, and the back of the butt joint is pressed tightly on the air-cooled-copper liner, and the copper liner Gas grooves and shielding gas passage holes for controlling the shape of the weld are processed on the pad; before laser welding, the shielding gas is pre-passed to the air-cooled-copper pad to drive away the air, and high-purity Ar is always fed to the copper pad during the welding process gas; carry out laser spot welding of butt joints, during the welding process, the laser beam completely melts through the welding, forming fusion holes, and realizing double-sided forming in one welding. The invention solves the difficult problem of Hass alloy welding and ensures the use quality of the conductive roller in the manufacturing process of the conductive roller of the electrogalvanizing unit of the automobile plate.

Description

A method for controlling the weld seam formation of Hass alloy conductive roller laser penetration welding

technical field

The present invention relates to laser welding seam forming control technology, in particular to a Hass alloy conductive roller laser penetration welding seam forming control method, especially suitable for I-type groove thick wall made of conductive roller of automobile plate electrogalvanizing unit Laser welding of Hass alloy materials.

Background technique

Hass alloy mainly uses wire-filled argon arc welding (GTAW welding). For thicker plates, manual argon tungsten arc welding (GTAW) is often used as a primer, and manual arc welding (SMAW) is used to cover the surface. It can also be welded Metal inert gas shielded welding (GMAW), submerged arc automatic welding (SAW) and other methods of welding.

In the prior art, Document 1 discloses "The welding metallurgy of HASTELLOYalloys C-4C-22 and C-267", using the GTAW method to weld C-4, C-22 and C-267 to study the thermal crack sensitivity of the material ; Literature 2 "Hastelloy C-22 alloy" introduces several common welding methods for Hass alloys: GTAW/GMAW/SAW; due to the high heat input of SAW, it is not recommended; Literature 3 "Hass corrosion-resistant alloy welding" Among them, it is recommended that Hass alloys with a thickness of more than 2mm be designed by open-groove GTAW, GMAW and SMAW welding processes.

It can be seen that the GTAW method is mainly used for Hass alloy welding, and the groove needs to be opened if it is more than 3mm. The use of multi-layer multi-pass welding will inevitably lead to a wide welding heat-affected zone (HAZ) and large welding residual stress; secondly, multi-layer multi-pass welding, welding Pores, inclusions, and incomplete fusion defects are easily formed in the seam; adding filler metal to the weld may lead to the formation of low-melting point compounds, induce welding hot cracks, and reduce the corrosion resistance of the weld.

Contents of the invention

The purpose of the present invention is to provide a method for controlling the formation of Hass alloy conductive roller laser penetration welding weld seam, which can solve the difficult problem of Hass alloy welding and ensure the use quality of the conductive roller in the production process of the conductive roller of the automobile plate electrogalvanizing unit .

To achieve the above object, the technical solution of the present invention is,

A Hass alloy conduction roller laser penetration welding seam forming control method, using Hass alloy steel plate for cylinder rounding, the edge of the plate of the butt joint before rounding is processed into a groove at a certain angle, and the butt joint is formed after rounding I-shaped groove; the rounded cylinder completes the joint assembly on the fixture; the laser welding seam forming control adopts air-cooled-copper liner to control the back shape of the weld seam, and the back of the butt joint is pressed tightly on the air-cooled-copper liner , the copper pad is processed with air grooves and shielding gas holes to control the shape of the weld; before laser welding, the shielding gas is pre-passed to the air-cooled-copper pad to drive away the air, and the copper pad is always kept in the welding process. High-purity Ar gas, Ar gas pressure 1-2kg, concentration 90-95%; adjust the alignment between the laser beam and the seam position, measure and adjust the welding torch height, set the laser welding parameters, etc., and then carry out the laser spot on the seam Solid welding: During the welding process, the laser beam completely penetrates the welding, forming a fusion hole, and realizing double-sided forming in one welding.

The above-mentioned welded double-sided forming can adopt a conventional laser welding process.

Further, in the double-sided forming control of laser penetration welding according to the present invention, the lead-in plate and the end point are added to the lead-in plate at the start point of the weld at both ends of the butt joint, and the lead-in plate section of the weld seam uses a high-power laser beam of 8-12kw, or low The speed parameter is 0.5-1.5m/min; after introducing the board, use a smaller laser power of 8-10kw or a faster welding speed of 1-2m/min for welding.

Laser penetration welding double-sided forming control, by setting the parameters of the weld seam in sections, different laser power or different welding speeds are used for welding different weld seam sections during the welding process, so as to achieve uniform penetration of the overall weld seam And forming control to ensure the consistency of the front and back of the weld.

During the laser welding process, the starting point and the end point of the weld are often prone to welding defects. In order to avoid welding defects at both ends of the weld, an lead-in plate and an end-point lead-out plate are added at the start of the weld at both ends of the butt joint.

The double-sided forming of the welding seam adopts LASER or GTAW wire-filling multi-pass welding for surface modification to obtain a smooth and defect-free welding seam.

Two Hass alloy steel plates are welded together without groove first, and then the cylinder is rounded, and the edge of the butt joint is processed into a groove before rounding.

The invention is used for laser welding the conduction roll of the casing structure of the hastealloy alloy cylinder. Both the plate butt joints and the longitudinal seam of the cylinder are welded by laser penetration, and the shape of the Hastealloy cylinder and the welding seam are arranged. It adopts I-type joint form, no need to add filler metal to the weld seam, and double-sided forming in one welding.

For butt welding of the longitudinal seam of the cylinder, the joint assembly is performed on the jig of the cylinder butt welding. When the cylinder is rounded, the ellipticity and dimensional accuracy of the cylinder must be strictly controlled. Before the rounding, the edge of the plate of the butt joint is processed into a certain angle groove, and the butt joint after the rounding just forms an I-shaped groove.

After the joint assembly is completed on the fixture, the centering adjustment between the laser beam and the seam position, the measurement and adjustment of the welding torch height, the setting of laser welding parameters, etc. are carried out, and then the laser spot welding of the butt seam is carried out. The distribution of solder joints and the size of solder joints on the butt joints should ensure that the butt joints after spot solidification have sufficient connection strength. The spacing of the laser spot solid solder joints of the present invention is 400mm, and the length of the spot solid solder joints is 3mm.

Laser welding seam shape control uses an air-cooled copper pad to control the backside shape of the weld. Air cooling - process the required welding seam shape control air groove on the copper pad, and air cooling - process several vent holes for the back protection gas on the copper pad. Before starting welding, it is necessary to pre-pass the protective gas to the back of the weld to drive away the air; during the welding process, always keep a certain pressure of high-purity Ar gas in the welding area and the back of the weld. The flowing Ar gas has the following functions: prevent the metal oxidation of the back weld and the generation of pores at the root of the weld, and air cooling-a certain flow of gas ejected from the copper liner improves the shape of the back weld.

Beneficial effects of the present invention

The electro-galvanizing process of automobile sheet not only puts forward very strict engineering application technical indicators for the dimensional accuracy of the outer Hass alloy cylinder of the conductive roller, but also for the surface and internal quality of the weld, and does not allow unfused, inclusions, voids, pores, etc. in the weld. Defects that can be detected by non-destructive testing such as thermal cracks require that the weld metal and the base metal have the same ability to resist corrosion by environmental media. It turns out that the conductive rollers are made of imported spare parts. In China, manual argon tungsten arc welding (GTAW) and manual arc welding (SMAW) were also tried to weld the surface, but they all failed.

The invention adopts laser penetration welding technology, laser welding has small beam diameter and high energy density, and it does not need to add filler metal to the welding seam, and realizes double-sided forming in one welding; moreover, the laser welding seam forming control adopts air cooling-copper Pad controls weld backside formation, air cooling - a flow of gas ejected from the copper pad improves the shape of the backside weld formation.

The invention can be used for the welding of Hass alloy with a thickness of 10mm, realizes single-sided welding and double-sided forming control, and ensures the technical index of the use of the Hass alloy conductive roller.

Description of drawings

Fig. 1 is a schematic diagram of the shape of the Hass alloy cylinder and the layout of the welding seam of the present invention.

Detailed ways

Referring to Fig. 1 , a method for controlling the formation of a Hass body conduction roller laser penetration welding seam according to the present invention uses a Hass alloy steel plate to round the cylinder, and the edge of the butt joint before the rounding is processed into a groove at a certain angle. The rounded butt joint forms an I-shaped bevel; the rounded cylinder 1 completes the joint assembly on the fixture; the lead-in plate is added at the starting point of the weld 2 at both ends of the butt joint and the lead-out plate is added at the end;

Laser welding seam shape control adopts air-cooled-copper liner to control the back shape of the weld seam, and the back of the butt joint is pressed against the air-cooled-copper liner, and the copper liner is processed with air grooves and shielding gas to control the shape of the weld seam Through hole; before laser welding, the protective gas is pre-passed to the air-cooled copper pad to drive away the air. During the welding process, high-purity Ar gas is always fed to the copper pad. The Ar gas pressure is 1-2kg and the concentration is 90-95%. ; Adjust the centering of the laser beam and the seam position, measure and adjust the height of the welding torch, set the laser welding parameters, etc., and then perform laser spot welding on the seam; the laser beam completely melts through the welding joint during the welding process to form a fusion hole , to achieve one-time welding double-sided forming.

Example 1

In this embodiment, the present invention is used for laser welding the conduction roller of the casing structure of the hastealloy alloy cylinder. The butt joints of the flat plate or the longitudinal seam of the cylinder are all welded by laser penetration, and the shape of the Hastealloy alloy cylinder and the arrangement of the welding seam are adopted. It adopts I-type joint form, no need to add filler metal to the weld seam, and double-sided forming in one welding. A gantry-type five-axis _CO2 laser welding machine is used for the welding of Hass alloy plate butt joints and cylinder butt joints. On the control platform, the laser welding machine is controlled by software programming, and the three-dimensional space position coordinates of the laser welding torch are adjusted to realize the height tracking of the laser welding torch relative to the weld seam and the centering of the laser beam and the center line of the weld seam.

In this embodiment, the welding process parameters are fixed: the laser power is 8KW, the welding speed is 1m/min, the defocus is -1mm, the length of the positioning solder joints is 3 mm, and the distance between the positioning solder joints is 400 mm. The process parameters used in continuous laser penetration welding: laser power is 8KW, welding speed is 1m/min, defocus is -1mm, Ar gas pressure is 2kg, concentration is 90%.

Example 2

In this embodiment, the present invention is used for laser welding the conduction roller of the casing structure of the hastealloy alloy cylinder. The butt joints of the flat plate or the longitudinal seam of the cylinder are all welded by laser penetration, and the shape of the Hastealloy alloy cylinder and the arrangement of the welding seam are adopted. I-type joints are adopted, and the 10.5mm thick Hass alloy steel plate does not need to be grooved, and there is no need to add filler metal to the weld, and it can be formed on both sides in one welding. A gantry-type five-axis _CO2 laser welding machine is used for the welding of Hass alloy plate butt joints and cylinder butt joints. On the control platform, the laser welding machine is controlled by software programming, and the three-dimensional space position coordinates of the laser welding torch are adjusted to realize the height tracking of the laser welding torch relative to the weld seam and the centering of the laser beam and the center line of the weld seam.

In this embodiment, the welding process parameters are fixed: laser power 10KW, welding speed 2m/min, defocus amount - 1mm, length of positioning solder joints 3 mm, distance between positioning solder joints 400 mm. Process parameters used in continuous laser penetration welding: laser power 10KW, welding speed 2m/min, defocus amount -1mm, Ar gas pressure 1kg, concentration 90%.

Claims (6)

1. Haas alloy conductive roll laser penetration welded seam shaping control method, it is round as a ball to carry out cylindrical shell with the Haas alloy-steel plate, round as a ball before the sheet edge of banjo fixing butt jointing be processed to groove, the abutment joint after round as a ball forms I type groove; Cylindrical shell after round as a ball is finished the joint assembling on anchor clamps; Laser weld is shaped to control and adopts air cooling-copper lining control back of weld to be shaped, and the abutment joint back side is pressed on air cooling-copper lining, processes the air drain and protection vent hole of control weld shape on the copper lining; Promptly to the logical in advance protective gas of air cooling-copper lining, drive air before the laser weld, remain in the welding process to copper lining and feed high-purity Ar gas, Ar atmospheric pressure 1-2kg, concentration 90-95%; Carry out the adjusting of laser beam and seaming position centering, torch height measurement and adjusting, abutment joint laser tack welding is carried out in laser weld parameter setting etc. then; The complete burn through welding of laser beam forms molten hole in the welding process, realizes once welding two-sides forming.

2. laser penetration welded seam shaping control method as claimed in claim 1, it is characterized in that, the control of described laser penetration weldering two-sides forming, weld seam starting point at the banjo fixing butt jointing two ends adds lead-in plate and terminal point adds end tab, weld seam lead-in plate section adopts high-power laser beam 8-12kw, or low speed of welding parameter 0.5-1.5m/min; Behind the lead-in plate, use less laser power 8-10kw again instead or very fast speed of welding 1-2m/min welds.

3. laser penetration welded seam shaping control method as claimed in claim 1 is characterized in that, described weld seam two-sides forming adopts LASER or GTAW silk filling multi-pass welding to carry out finishing, obtains smooth, flawless weld seam.

4. laser penetration welded seam shaping control method as claimed in claim 1 is characterized in that, the sheet edge of round as a ball preceding banjo fixing butt jointing is processed to the groove of 30 °-45, and the abutment joint after round as a ball forms I type groove, and the abutment joint clearance control is at 1-2mm.

5. laser penetration welded seam shaping control method as claimed in claim 1 is characterized in that the spacing of laser tack-weld is 300-400mm, and the length of tack-weld is 3-5mm.

6. laser penetration welded seam shaping control method as claimed in claim 1 is characterized in that, two Haas alloy-steel plates elder generation square grooves are integrally welded, and then it is round as a ball to carry out cylindrical shell, round as a ball before the sheet edge of banjo fixing butt jointing be processed to groove.

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