阅读说明：本技术 一种超级奥氏体双相不锈钢管与船用高强板的焊接方法 (Welding method of super austenitic duplex stainless steel pipe and marine high-strength plate ) 是由 张明高 陈建军 陈爽 高世磊 于 2020-11-09 设计创作，主要内容包括：本发明提供了一种超级奥氏体双相不锈钢钢管与船用高强板的焊接方法,对船用高强板预先形成堆焊隔离层,使隔离层材料成分接近超级奥氏体双相不锈钢管的成分,在通过隔离层与超级奥氏体双相不锈钢管进行焊接,焊接时采用合理的焊接参数、焊接顺序及控制措施。本发明的有益效果是：降低异种钢焊接易出现焊接热裂纹缺陷的概率,提高焊接质量。(The invention provides a welding method of a super austenite duplex stainless steel pipe and a ship high-strength plate, wherein a surfacing isolation layer is formed on the ship high-strength plate in advance, the material composition of the isolation layer is close to that of the super austenite duplex stainless steel pipe, the isolation layer and the super austenite duplex stainless steel pipe are welded, and reasonable welding parameters, welding sequence and control measures are adopted during welding. The invention has the beneficial effects that: the probability of welding thermal crack defects easily occurring in dissimilar steel welding is reduced, and the welding quality is improved.)

1. A welding method of a super austenite duplex stainless steel pipe and a marine high-strength plate is characterized in that a surfacing isolation layer is formed on the marine high-strength plate in advance, the components of the isolation layer are close to those of the super austenite duplex stainless steel pipe, and the super austenite duplex stainless steel pipe is welded through the isolation layer, and the welding method comprises the following specific steps:

firstly, surfacing welding pretreatment of an isolation layer: polishing the cleanliness and the groove of the welding seam of the marine high-strength steel plate;

step two, carrying out isolated layer surfacing welding on the marine high-strength plate: under the unconstrained condition, a plurality of layers of multi-pass surfacing cladding metal layers are sequentially carried out by adopting nickel-based welding materials and argon arc welding, the welding is carried out at intervals, and the temperature between surfacing layers is controlled to be less than 100 ℃;

step three, adjusting the assembly gap between the super austenitic duplex stainless steel pipe and the marine high-strength plate to ensure that the gaps on the two sides are uniform;

welding the isolation layer and the super austenitic duplex stainless steel pipe: positioning the super austenitic duplex stainless steel pipe, and dividing the super austenitic duplex stainless steel pipe into eight symmetrical positions for welding;

after the symmetrical positioning welding in the step four, adopting a sixteen-layer symmetrical welding method to control the generation of integral welding stress and defects at joints, welding the first layer sixteen-layer symmetrical welding, covering a front welding joint at a rear welding joint, knocking by a wooden mallet to eliminate stress, and polishing and checking the joints; when the second layer is welded, the second layer is rotated by 30 degrees, welding is carried out by adopting a sixteen-part symmetrical welding method again, and the welding joints of the second layer completely cover the welding joints of the first layer, so that the integral welding quality of the joints is ensured; welding the third layer to the sixteenth layer by the same method in sequence until the welding is finished, wherein the interval welding time of each layer meets the condition that the temperature between overlaying layers is less than 100 ℃;

and sixthly, polishing and detecting flaws after the welding is integrally completed.

2. The welding method of the super austenitic duplex stainless steel pipe and the marine high-strength plate according to claim 1, characterized in that: and step two, the cladding metal layer is more than three layers.

3. The welding method of the super austenitic duplex stainless steel pipe and the marine high-strength plate according to claim 1, characterized in that: in the second step and the fifth step, after welding of each layer is finished, a mallet is used for knocking, and part of welding stress is released.

4. The welding method of the super austenitic duplex stainless steel pipe and the marine high-strength plate according to claim 1, characterized in that: the welding length of the step five is 20-40 mm.

Technical Field

The invention belongs to the technical field of welding of super austenitic duplex stainless steel, and particularly relates to a welding method of a super austenitic duplex stainless steel pipe and a marine high-strength plate.

Background

According to the definition of MEPC.259(68) of the global sea area ship sulfur limit regulation, the emission of the sulfur oxides in the flue gas for ships is required to be less than 0.5% on the year 2020, the day 01. The market continues red fire with the extra equipment of boats and ships desulfurizing tower, and the material of desulfurizing tower washing has strong acid corrosivity, and connecting material must also possess and resist strong acid corrosivity. The super austenite duplex stainless steel is a novel high-alloy pure stainless steel, which is between common austenite stainless steel and nickel-based alloy, contains higher Mo Cr Si Cu and other alloy elements, and improves the stability and corrosion resistance of austenite structure. In some cases, the alloy can be compared with the Hastelloy. Therefore, the welding of the super austenitic stainless steel and the marine high-strength plate is inevitable in the ship construction process.

The welding of the super austenite duplex stainless steel and the same steel is easy to generate hot cracks, and the welding problem of the super austenite duplex stainless steel and the marine high-strength plate is easy to generate. The main reasons are that the super austenitic duplex stainless steel contains high nickel, is easy to form low-melting eutectic with S and P, the marine high-strength plate has higher content than S P in the super austenitic duplex stainless steel, and the welding of dissimilar steel is easy to crack. Secondly, the welding seam is a single-phase austenite columnar crystal structure, and is easy to cause impurity segregation and the formation of an intercrystalline liquid film, so that when the welding seam is welded with the marine high-strength steel plate, the fusion crystal is easy to generate welding cracks. And thirdly, in the fusion and solidification process of the welding metal, certain assembly stress exists in assembly due to larger stress existing in expansion with heat and contraction with cold, and welding cracks are easy to generate under the condition that the welding metal does not have enough strength to resist the stress. The super austenitic duplex stainless steel and the high-strength carbon steel have great difference in physical properties, the resistance of the super austenitic duplex stainless steel is 5 times that of the carbon steel, the heat conductivity of the super austenitic duplex stainless steel is low and is about one third of that of the carbon steel, so that the heat transfer speed of the super austenitic duplex stainless steel is slow, the thermal deformation is increased, and the post-welding stress is great.

Disclosure of Invention

In view of the above problems, the present invention aims to provide a welding method for a super austenitic duplex stainless steel pipe and a marine high-strength plate, which reduces heat input amount in the welding process and improves the performance of a joint through a low P S nickel-based welding material with good weldability, sufficient strength toughness and reasonable welding parameters, thereby achieving high-efficiency and high-quality welding of dissimilar steels. The welding construction difficulty of pure austenitic stainless steel and dissimilar steel is reduced, and the welding quality is improved.

In order to achieve the purpose, the invention adopts the technical scheme that: a welding method of a super austenite duplex stainless steel pipe and a marine high-strength plate is characterized in that a surfacing isolation layer is formed on the marine high-strength plate in advance, the components of the isolation layer are close to those of the super austenite duplex stainless steel pipe, and the super austenite duplex stainless steel pipe is welded through the isolation layer, and the welding method comprises the following specific steps:

firstly, surfacing welding pretreatment of an isolation layer: polishing the cleanliness and the groove of the welding seam of the marine high-strength steel plate;

step two, carrying out isolated layer surfacing welding on the marine high-strength plate: under the unconstrained condition, a plurality of layers of multi-pass surfacing cladding metal layers are sequentially carried out by adopting nickel-based welding materials and argon arc welding, the welding is carried out at intervals, and the temperature between surfacing layers is controlled to be less than 100 ℃;

step three, adjusting the assembly gap between the super austenitic duplex stainless steel pipe and the marine high-strength plate to ensure that the gaps on the two sides are uniform;

welding the isolation layer and the super austenitic duplex stainless steel pipe: positioning the super austenitic duplex stainless steel pipe, and dividing the super austenitic duplex stainless steel pipe into eight symmetrical positions for welding;

after the symmetrical positioning welding in the fifth step, adopting a sixteen-layer symmetrical welding method to control the generation of integral welding stress and defects at joints, welding the first layer sixteen-layer symmetrical welding, covering a front welding joint at a rear welding joint, knocking by a wooden mallet to eliminate stress, and polishing and checking the joints; when the second layer is welded, the second layer is rotated by 30 degrees, welding is carried out by adopting a sixteen-part symmetrical welding method again, and the welding joints of the second layer completely cover the welding joints of the first layer, so that the integral welding quality of the joints is ensured; welding the third layer to the sixteenth layer by the same method in sequence until the welding is finished, wherein the interval welding time of each layer meets the condition that the temperature between overlaying layers is less than 100 ℃;

and sixthly, polishing and detecting flaws after the welding is integrally completed.

And the number of the cladding metal layers in the step two is more than three.

In the second step and the sixth step, after welding of each layer is finished, a mallet is used for knocking, and part of welding stress is released.

The welding length of the step six is 20-40 mm.

The invention has the following effects: by adopting the welding method, the welding heat input quantity is reduced and the defect generation probability is reduced by utilizing high-performance welding materials and reasonable welding parameters. Meanwhile, the welding of the isolation transition layer avoids the problem of welding cracks in the process of fusing dissimilar steels, and then various problems such as cracks and the like caused by welding the super austenitic duplex stainless steel and the marine high-strength plate are completely avoided by reasonable welding sequence control and stress relief measures. Provides a welding idea and method for welding other dissimilar steels.

Drawings

FIG. 1 is a schematic diagram of a super austenitic duplex stainless steel pipe and a marine high-strength plate structure according to the present invention;

FIG. 2 is a schematic diagram of the welding position of the super austenitic duplex stainless steel pipe and the marine high-strength plate structure according to the present invention;

FIG. 3 is a schematic view of a welding structure of the present invention for build-up welding of the isolation layer on the marine high-strength plate;

FIG. 4 is a schematic view of the positioning of a superaustenitic duplex stainless steel tube according to the present invention;

FIG. 5 is a schematic view of the layered welding of the superaustenitic duplex stainless steel tube of the present invention;

FIG. 6 is a schematic groove of the present invention;

fig. 7 is a weld bead arrangement and welding sequence of the present invention.

In the figure:

1. super austenite duplex stainless steel pipe 2, marine high-strength plate

3. Build-up welding isolation layer 4 and build-up welding isolation layer

5 build-up welding isolation layer

Detailed Description

The invention is described in further detail below with reference to the following figures and detailed description:

the welding difficulty of the super austenite duplex stainless steel and the marine high-strength plate is that the super austenite duplex stainless steel is very easy to weld due to the particularity of the material, and the cladding metal is easy to weld due to the fusion with the marine high-strength plate and other dissimilar steels. The key point of the invention is to establish a surfacing layer by welding materials, thereby welding dissimilar steels into welding similar to the same steel, and achieving the aim of flawless welding by reasonable welding parameters, sequence and welding method.

As shown in fig. 1 to 7, the welding method of the super austenitic duplex stainless steel pipe and the marine high-strength plate of the invention comprises the following steps: firstly, a surfacing isolation layer is formed on the marine high-strength plate 2 in advance, so that the material composition of the isolation layer is close to that of the super austenite duplex stainless steel pipe 1, and then the isolation layer is welded with the super austenite duplex stainless steel pipe 1.

The method comprises the following specific steps:

step one, carrying out pre-welding polishing treatment on the high-strength steel plate by using an isolation layer surfacing: and metal luster and no oil stain rust are ground within the range of 50mm around the welding line, and the cleanliness is ensured to meet the quality requirement. The group alignment misalignment is within 0.5mm tolerance, the groove angle is processed according to positive tolerance, and the groove angle is larger than a normal groove angle.

And secondly, adopting argon arc welding in the welding process, and adopting nickel-based welding materials for surfacing under the unconstrained condition, wherein the welding parameters are as follows:

and step three, overlaying a cladding metal layer in sequence, and controlling the temperature between overlaying layers to be not more than 100 ℃. And after welding of each surfacing layer is finished, knocking by using a wooden mallet, releasing part of welding stress, finding defects and polishing.

Step four, positioning the welded pipe: the welding process is divided into eight symmetrical positioning weldings, and the welding length is about 30 mm. And checking the quality of the tack welding, particularly the arc starting and arc stopping positions.

And fifthly, adopting a sixteen-minute layered symmetrical welding method to control the generation of integral welding stress and defects at joints. And sixteenth welding is symmetrically performed on the first layer of welding, the front welding head is covered at the rear welding head, the stress is eliminated by the knocking of a wooden mallet, and the joint is polished and checked.

When the second layer is welded, the welding head rotates by 30 degrees, the welding head is welded by adopting a sixteen-minute symmetrical welding method again, and the welding head of the first layer is completely covered by the welding head of the second layer, so that the overall welding quality of the joint is ensured.

And welding the third layer, the fourth layer and the subsequent layers in the same method in sequence until the welding is finished. The temperature between each layer is less than 100 ℃, and after welding of each layer is completed, a mallet is adopted to hammer to eliminate welding stress.

The welding parameters were as follows:

and sixthly, polishing and detecting flaws after the welding is integrally completed.