CN-121988930-A - Material and method for double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for water-cooled wall

CN121988930ACN 121988930 ACN121988930 ACN 121988930ACN-121988930-A

Abstract

The invention discloses a material for a double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for a water-cooled wall, which comprises a water-cooled wall metallurgical bonding layer welding wire for surfacing of the surface of the water-cooled wall and a water-cooled wall high-temperature-resistant erosion layer welding wire for surfacing of the metallurgical bonding layer. The surfacing layer prepared from the material has high metallurgical bonding strength with the water wall matrix, and excellent high-temperature corrosion resistance, so that the water wall tube can be effectively protected, and the tube explosion accident caused by high-temperature erosion of the water wall can be avoided. Also discloses a preparation method of the material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall.

Inventors

CHU QIAOLING
BAI JIALE
LIU JIN
LIU RUOXUAN
WANG ZHIKUN
WANG JUNYAO
YANG DAN

Assignees

西安理工大学

Dates

Publication Date: 20260508
Application Date: 20260306

Claims (9)

1. The material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall is characterized by comprising a water-cooled wall metallurgical bonding layer welding wire for surfacing the surface of the water-cooled wall and a water-cooled wall high-temperature-resistant erosion layer welding wire for surfacing the surface of the metallurgical bonding layer.
2. The material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall, which is characterized in that the welding wire for the metallurgical bonding layer of the water-cooled wall comprises 70.0-80.0% of Fe, 8.0-10.0% of Cr, 1.0-3.0% of Nb, 1.0-2.0% of Mo, 1.0-2.0% of Co, 1.0-2.0% of Y 2 O 3 and the balance of Ni, wherein the mass percentage of the components is 100%; The water-cooled wall high-temperature-resistant erosion layer welding wire comprises 40.0-50.0% of Cr, 25.0-30.0% of Nb, 3.0-5.0% of Al, 3.0-5.0% of Mo, 1.0-2.0% of Co, 1.0-2.0% of C, 0.5-1.0% of Y 2 O 3 and the balance of Ni in percentage by mass, wherein the sum of the components is 100%.
3. The material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall, according to claim 2, wherein the purity of each raw material component powder in the welding wire for the metallurgical bonding layer of the water-cooled wall and the welding wire for the high-temperature erosion-resistant layer of the water-cooled wall is more than or equal to 99.9%.
4. The material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall, which is disclosed in claim 2, is characterized in that the granularity of each raw material component powder in the water-cooled wall metallurgical bonding layer welding wire and the water-cooled wall high-temperature erosion-resistant layer welding wire is 100-200 meshes.
5. The material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall according to claim 2, wherein the welding pads used for the welding wire for the metallurgical bonding layer of the water-cooled wall and the welding wire for the high-temperature erosion-resistant layer of the water-cooled wall are both Inconel 625 strips, the thicknesses of the welding pads are both 0.4mm, and the widths of the welding pads are both 7mm.
6. The material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall according to claim 2, wherein the filling rates of the welding wire for the metallurgical bonding layer of the water-cooled wall and the welding wire for the high-temperature erosion-resistant layer of the water-cooled wall are controlled to be 22-25 wt%.
7. The material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall, which is disclosed in claim 2, is characterized in that the preparation method of the welding wire for the metallurgical bonding layer of the water-cooled wall comprises the following specific steps: The method comprises the following steps of 1, respectively weighing 70.0-80.0% of Fe, 8.0-10.0% of Cr, 1.0-3.0% of Nb, 1.0-2.0% of Mo, 1.0-2.0% of Co, 1.0-2.0% of Y 2 O 3 and the balance of Ni according to mass percentages, wherein the sum of the mass percentages of the components is 100%; step 2, the powder weighed in the step 1 is placed in a vacuum heating furnace for heating, the heating temperature is 220-260 ℃, the heat preservation time is 1-3 hours, crystal water in the powder is removed, and the dried powder is placed in a powder mixer for full mixing for 1-3 hours; Step 3, using an Inconel 625 band as a welding skin, removing grease on the surface of the Inconel 625 band by adopting alcohol, wrapping the medicinal powder prepared in the step 2 in the Inconel 625 band by using flux-cored wire drawing equipment, wherein the aperture of a first drawing die is 2.6mm; step 4, after the first procedure is finished, the aperture of the die is sequentially reduced, and finally the flux-cored wire with the diameter of 1.2mm is obtained; And 5, winding the flux-cored wire on a wire reel through a wire winding machine after the flux-cored wire is drawn, and finally sealing the flux-cored wire in a flux-cored wire vacuum packaging bag for later use.
8. The material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall, which is disclosed in claim 2, is characterized in that the preparation method of the welding wire for the high-temperature-resistant erosion-resistant layer of the water-cooled wall comprises the following specific steps: The method comprises the following steps of 1, weighing 40.0-50.0% of Cr, 25.0-30.0% of Nb, 3.0-5.0% of Al, 3.0-5.0% of Mo, 1.0-2.0% of Co, 1.0-2.0% of C, 0.5-1.0% of Y 2 O 3 and the balance of Ni according to mass percentages, wherein the sum of the mass percentages of the components is 100%; Step 2, the powder weighed in the step 1 is placed in a vacuum heating furnace for heating, the heating temperature is 240-280 ℃, the heat preservation time is 2-4 hours, crystal water in the powder is removed, and the dried powder is placed in a powder mixer for full mixing, wherein the mixing time is 2-4 hours; Step 3, using an Inconel 625 band as a welding skin, removing grease on the surface of the Inconel 625 band by adopting alcohol, wrapping the medicinal powder prepared in the step 2 in the Inconel 625 band by using flux-cored wire drawing equipment, wherein the aperture of a first drawing die is 2.6mm; step 4, after the first procedure is finished, the aperture of the die is sequentially reduced, and finally the flux-cored wire with the diameter of 1.2mm is obtained; And 5, winding the flux-cored wire on a wire reel through a wire winding machine after the flux-cored wire is drawn, and finally sealing the flux-cored wire in a flux-cored wire vacuum packaging bag for later use.
9. The preparation method of the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall is characterized by adopting the material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall according to claim 2, and specifically comprises the steps of firstly, directly surfacing a welding wire of a metallurgical bonding layer of the water-cooled wall on the surface of the water-cooled wall, wherein the surfacing is performed by adopting a CMT power supply, the surfacing current is 120A-160A, the thickness of the surfacing layer is 1.5 mm-2.0 mm, and secondly, surfacing the surface of the metallurgical bonding layer obtained in the first step by adopting the welding wire of the high-temperature erosion-resistant surfacing layer of the water-cooled wall, wherein the surfacing is performed by adopting a CMT power supply, the surfacing current is 160A-250A, and the thickness of the surfacing layer is 1.5 mm-2.0 mm.

Description

Material and method for double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for water-cooled wall Technical Field The invention belongs to the technical field of metal materials, and particularly relates to a material for a double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for a water wall and a preparation method of the material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water wall. Background With the development of the coal-fired thermal generator set to the high-parameter and high-capacity direction, the working environment of the water-cooled wall of the boiler is more and more harsh. In the running process, the water-cooled wall heating surface not only bears the intense heat radiation of high-temperature flame in the furnace, but also faces the high-speed erosion and abrasion of a large amount of fly ash particles generated by pulverized coal combustion. Particularly, when low-calorific-value and high-ash-content inferior coal is burned, the fly ash concentration is higher, and particles are harder, so that the wall of the water wall pipe is rapidly thinned due to scouring, and the low-calorific-value and high-ash-content inferior coal becomes one of key factors limiting the service life of the water wall pipe. Meanwhile, sulfur element in the fire coal can generate complex vulcanization reaction with metal on the pipe wall at high temperature, so that high-temperature sulfur corrosion is caused, and the failure process of the material is further accelerated. The interaction of erosive wear and high-temperature corrosion makes the protection problem of the water-cooled wall become extremely severe, and the safety and economical operation of the boiler are directly related. Aiming at the problems, the service life of the water-cooled wall is prolonged by adopting a surface protection technology in the industry at present, wherein the surfacing technology is widely applied because of the advantages of high bonding strength, good shock resistance and the like due to the fact that the surfacing technology can form a cladding layer metallurgically bonded with a matrix. However, conventional weld overlay material designs tend to focus on single performance enhancements, such as increased hardness or corrosion resistance of the weld overlay by increasing the alloying element content. However, under actual service conditions, the water wall surfacing layer faces the dual performance requirements of 'inside' and 'outside', namely, on one hand, the surfacing layer needs to realize good metallurgical bonding with a substrate (water wall pipe, usually low carbon steel or low alloy steel), and a part close to the substrate needs to have certain plasticity and toughness to buffer thermal stress and mechanical stress and avoid interface cracking or peeling, and on the other hand, the surfacing layer surface layer is directly exposed to high-temperature flame and corrosive smoke and has extremely high red hardness, wear resistance and corrosion resistance. This significant difference in internal and external performance requirements makes it difficult to simultaneously meet a single homogeneous weld overlay. In recent years, there have been some drawbacks in attempting to optimize performance by multilayer build-up or adjusting alloy composition. For example, although a simple high alloy overlay layer has excellent surface properties, it is prone to cause a large residual stress at the interface due to a large difference in thermal physical properties (such as linear expansion coefficient) between the overlay layer and the substrate, resulting in a decrease in bonding properties and even flaking of the overlay layer. The transition layer combined with the base material is emphasized too much, and the wear resistance and corrosion resistance of the surface layer are not expected. Therefore, how to balance the bonding performance of the build-up layer and the substrate and the working performance of the surface layer to achieve both of them becomes a technical problem to be solved in the art. Disclosure of Invention The invention aims to provide a material for a double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for a water wall, which is prepared to obtain a surfacing layer which has high metallurgical bonding strength with a water wall matrix on one hand and excellent high-temperature corrosion resistance on the other hand, and can effectively protect a water wall pipe and avoid pipe explosion accidents under high-temperature erosion of the water wall. The second purpose of the invention is to provide a preparation method of the material for the double-gradient low-stress wear-resistant corrosion-resistant surfacing layer for the water-cooled wall. The first technical scheme adopted by the invention is that the material for the double-gradient low-stress wear-resistant corrosion-resista