Wear-resistant coating material for impeller of slurry pump in alumina plant and preparation method thereof
阅读说明：本技术 一种用于氧化铝厂渣浆泵叶轮抗磨蚀涂层材料及制备方法 (Wear-resistant coating material for impeller of slurry pump in alumina plant and preparation method thereof ) 是由 霍凤萍 陈海涛 董思远 于 2021-08-18 设计创作，主要内容包括：一种用于氧化铝厂渣浆泵叶轮抗磨蚀涂层材料及制备方法。本发明属于表面处理技术领域,涉及用激光熔覆工艺制备耐磨蚀涂层,具体涉及一种用于氧化铝厂渣浆泵叶轮抗磨蚀工况下涂层材料及其工艺方法。所述激光复合制造铝矿浆泵叶轮的涂层材料,是由包括以下质量百分比组分组成：1.5～2％C、20～22％Mo、2～3％Si、14～16％Cr、30～32％Co、0.2～0.8％Ti、余量为Fe和不可避免的杂质。本发明熔覆装置采用良好的气氛保护装置,熔覆层中无气孔、缺陷及夹杂物,熔覆层纯净度高,热处理后有较高的抗冲击能力。(An abrasion-resistant coating material for an impeller of a slurry pump in an alumina plant and a preparation method thereof. The invention belongs to the technical field of surface treatment, relates to a laser cladding process for preparing an abrasion-resistant coating, and particularly relates to a coating material for an impeller of a slurry pump in an alumina plant under an abrasion-resistant working condition and a process method thereof. The coating material for laser composite manufacturing of the impeller of the aluminum slurry pump comprises the following components in percentage by mass: 1.5-2% of C, 20-22% of Mo, 2-3% of Si, 14-16% of Cr, 30-32% of Co, 0.2-0.8% of Ti, and the balance of Fe and inevitable impurities. The cladding device adopts a good atmosphere protection device, the cladding layer has no air holes, defects and inclusions, the purity of the cladding layer is high, and the cladding layer has higher impact resistance after heat treatment.)
1. The coating material for laser composite manufacturing of the impeller of the aluminum ore slurry pump is characterized by comprising the following components in percentage by mass: 1.5-2% of C, 20-22% of Mo, 2-3% of Si, 14-16% of Cr, 30-32% of Co, 0.2-0.8% of Ti, and the balance of Fe and inevitable impurities, wherein the sum of the mass percentages of the components is one hundred percent.
2. The coating material for laser composite manufacturing of an aluminum slurry pump impeller as claimed in claim 1, wherein the particle size of each component is-125 to +300 mesh.
3. The coating material for laser composite manufacturing of the impeller of the aluminum slurry pump according to claim 1, wherein the powders are proportioned by mass ratio, placed in a blender for mixing and subjected to vacuum drying treatment in use.
4. A process method for laser composite manufacturing of an impeller of an aluminum slurry pump comprises the following process steps: re-optimizing the substrate according to the use working condition, cladding a functional layer on the surface of the substrate, cladding a 0.8-1.2mm corrosion-resistant and wear-resistant functional layer by using a method of synchronous powder feeding atmosphere protection, carrying out heat treatment on the impeller after laser cladding, and finally carrying out finish machining to the specified size and precision; the method comprises the following specific steps:
(1) adding a new matrix machine: performing surface nondestructive testing on a cladding size chart of a 2Cr13 matrix machine addition impeller without defects;
(2) laser cladding: performing laser cladding on 1.5-2% of C, 20-22% of Mo, 2-3% of Si, 14-16% of Cr, 30-32% of Co, 0.2-0.8% of Ti and the balance of Fe and inevitable impurities; preheating an impeller at 180-200 ℃, and carrying out laser cladding on an anti-fatigue wear-resistant functional layer with the thickness of 0.8-1.2mm by using a fiber laser and matching with a laser synchronous powder feeding device; the adopted fiber laser has the parameters as follows: the focal length f of the focusing mirror is 300 mm; the cladding power P is 2500-3000W; the diameter D of the light spot is 3 mm; the cladding scanning speed V is 1000-2000 mm/min; the lapping rate is 50%;
(3) and (3) heat treatment: carrying out heat treatment on the aluminum slurry pump impeller repaired by laser cladding in the step (2) by adopting a vacuum heat treatment furnace, wherein the heat treatment process comprises the following steps: tempering at 550 ℃, preserving heat for 120 minutes and air cooling;
(4) fine machining to specified size and precision: the hardness of the laser cladding functional layer is HRC 58-HRC 60.
Technical Field
The invention belongs to the technical field of surface treatment, relates to a laser cladding process for preparing an abrasion-resistant coating, and particularly relates to an abrasion-resistant coating material for an impeller of a slurry pump in an alumina plant and a process method thereof.
Background
The aluminum pulp pump is the main equipment for conveying aluminum pulp in an alumina plant, and flow passage parts such as a pump shell, an impeller and the like are consumable parts. The aluminum slurry pump has harsh working conditions, is mainly characterized by high temperature and strong alkali, is usually 80-100 ℃ in temperature, has a PH value more than 14, and is a medium with extremely strong corrosivity. The aluminum ore is mainly diaspore with the component (w%) of AL2O3 60-65、Fe2O3 14-17、SiO2 3.2-4.5、TiO23.5-4.5, the overflowing media are hard particles, and the abrasion is serious. Most of the aluminum slurry pump impellers are made of high-chromium cast iron at present. Based on the analysis of the structure and the performance, the failure mode is that under the combined action of strong alkali and low-angle erosive wear, the carbide is separated from the matrix due to the severe corrosion of the carbide phase boundary, good support is lost, the erosive wear of ore pulp promotes the initiation and the expansion of cracks, the stripping of the matrix is accelerated, and the matrix is failed, so that the service efficiency of the pump is influenced.
Disclosure of Invention
In view of the problems in the prior art, the invention aims to provide a powder material for abrasion resistance of an impeller of an alumina slurry pump and a laser composite impeller manufacturing process method, based on failure analysis, the coating material provided by the invention can resist strong base corrosion, has good abrasion resistance and better abrasion resistance, and has the hardness of about 60 HRC. Through the process, the surface of the impeller is subjected to laser cladding, corrosion resistance and abrasion resistance, has certain impact toughness, and the service life of the impeller is prolonged, so that the service life of the whole pump is prolonged.
In order to achieve the purpose, the invention adopts the following technical scheme.
The coating material for laser composite manufacturing of the impeller of the aluminum ore slurry pump comprises the following components in percentage by mass: 1.5-2% of C, 20-22% of Mo, 2-3% of Si, 14-16% of Cr, 30-32% of Co, 0.2-0.8% of Ti, and the balance of Fe and inevitable impurities, wherein the sum of the mass percentages of the components is one hundred percent.
Wherein the granularity of each component is-125 to +300 meshes.
A powder preparation method for repairing an aluminum slurry pump impeller comprises the following steps: and (3) proportioning the powder with the granularity of-125 to +300 meshes according to the mass ratio, placing the powder into a mixer for mixing, and performing vacuum drying treatment when in use.
A process method for laser composite manufacturing of an impeller of an aluminum slurry pump comprises the following process steps: and (3) re-optimizing the substrate according to the use working condition, cladding a functional layer on the surface of the substrate, cladding a 0.8-1.2mm corrosion-resistant and wear-resistant functional layer by using a method of synchronous powder feeding atmosphere protection, carrying out heat treatment on the impeller subjected to laser cladding, and finally carrying out finish machining to the specified size and precision.
A process method for laser composite manufacturing of an impeller of an aluminum slurry pump comprises the following specific steps:
(1) the new matrix is added.
And (3) adding an impeller cladding size chart to the preferable 2Cr13 matrix machine, and performing surface nondestructive testing without defects.
(2) And (4) laser cladding.
Performing laser cladding on 1.5-2% of C, 20-22% of Mo, 2-3% of Si, 14-16% of Cr, 30-32% of Co, 0.2-0.8% of Ti and the balance of Fe and inevitable impurities; preheating an impeller at 180-200 ℃, and carrying out laser cladding on an anti-fatigue wear-resistant functional layer with the thickness of 0.8-1.2mm by using a fiber laser and matching with a laser synchronous powder feeding device; the adopted fiber laser has the parameters as follows: the focal length f of the focusing mirror is 300 mm; the cladding power P is 2500-3000W; the diameter D of the light spot is 3 mm; the cladding scanning speed V is 1000-2000 mm/min; the lapping rate is 50%.
(3) And (6) heat treatment.
Carrying out heat treatment on the aluminum slurry pump impeller repaired by laser cladding in the step (2) by adopting a vacuum heat treatment furnace, wherein the heat treatment process comprises the following steps: tempering at 550 ℃, preserving heat for 120 minutes and air cooling.
(4) And finishing to specified size and precision.
The hardness of the laser cladding functional layer is HRC 58-HRC 60.
Compared with the prior production and manufacturing process and method, the laser cladding technology is used for manufacturing the impeller of the aluminum ore slurry pump, the base body is optimized again, the base body has enough obdurability, the laser manufacturing functional layer has better strong base corrosion resistance and abrasion resistance, the risk of manufacturing the impeller is small, and the service life of the composite manufactured impeller is long.
Compared with the prior art, the invention has the following beneficial effects.
In the coating material for laser composite manufacturing of the impeller of the aluminum ore slurry pump, the content of C is controlled to be 1.5-2%, so that the impact resistance of a cladding layer is ensured, the strength is sufficient, a certain amount of strong carbide can be formed, and the wear resistance is improved. Mo in the coating material mainly has the functions of improving hardenability, improving mechanical properties, particularly improving toughness and improving the wear resistance of steel. The addition of a proper amount of Ti in the coating material not only can purify the crystal boundary, but also can precipitate and harden to separate out fine carbides in the heat treatment process, and has secondary hardening effect.
The Co, Mo and Si elements with specific contents in the coating material for laser composite manufacturing of the impeller of the aluminum ore slurry pump can be precipitated into an intermetallic compound Co with a topological close-packed structure in the heat treatment process3Mo2Si is a Laves phase, has good strength, high hardness and good corrosion resistance, but the Laves phase is easy to crack due to too high content.
The wear-resistant phase of the invention is the carbide and the Laves phase, and the two phases are reinforced together, thereby ensuring the wear resistance and having excellent strong base corrosion resistance.
Based on specific material design, the invention can form primary carbide and a biocarbide strengthening phase after cladding, the hardness after cladding is about 52HRC, the coating has no cracks, the hardness after heat treatment can reach about 58HRC, and the Co generated after secondary hardening3Mo2Si, namely the Laves phase strengthens the matrix, and obtains good wear resistance under the combined action of the Si, namely the Laves phase and the carbide, and the salt spray test grade can also reach 72 hours and 9 grades.
The cladding device adopts a good atmosphere protection device, the cladding layer has no air holes, defects and inclusions, the purity of the cladding layer is high, and the cladding layer has higher impact resistance after heat treatment.
Detailed Description
The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
The coating material for laser composite manufacturing of the impeller of the aluminum ore slurry pump comprises the following components in percentage by mass: 1.5-2% of C, 20-22% of Mo, 2-3% of Si, 14-16% of Cr, 30-32% of Co, 0.2-0.8% of Ti, and the balance of Fe and inevitable impurities, wherein the sum of the mass percentages of the components is one hundred percent.
Wherein the granularity of each component is-125 to +300 meshes.
A powder preparation method for repairing an aluminum slurry pump impeller comprises the following steps: and (3) proportioning the powder with the granularity of-125 to +300 meshes according to the mass ratio, placing the powder into a mixer for mixing, and performing vacuum drying treatment when in use.
A process method for laser composite manufacturing of an impeller of an aluminum slurry pump comprises the following process steps: and (3) re-optimizing the substrate according to the use working condition, cladding a functional layer on the surface of the substrate, cladding a 0.8-1.2mm corrosion-resistant and wear-resistant functional layer by using a method of synchronous powder feeding atmosphere protection, carrying out heat treatment on the impeller subjected to laser cladding, and finally carrying out finish machining to the specified size and precision.
A process method for laser composite manufacturing of an impeller of an aluminum slurry pump comprises the following specific steps:
(1) the new matrix is added.
And (3) adding an impeller cladding size chart to the preferable 2Cr13 matrix machine, and performing surface nondestructive testing without defects.
(2) And (4) laser cladding.
Performing laser cladding on 1.5-2% of C, 20-22% of Mo, 2-3% of Si, 14-16% of Cr, 30-32% of Co, 0.2-0.8% of Ti and the balance of Fe and inevitable impurities; preheating an impeller at 180-200 ℃, and carrying out laser cladding on an anti-fatigue wear-resistant functional layer with the thickness of 0.8-1.2mm by using a fiber laser and matching with a laser synchronous powder feeding device; the adopted fiber laser has the parameters as follows: the focal length f of the focusing mirror is 300 mm; the cladding power P is 2500-3000W; the diameter D of the light spot is 3 mm; the cladding scanning speed V is 1000-2000 mm/min; the lapping rate is 50%.
(3) And (6) heat treatment.
Carrying out heat treatment on the aluminum slurry pump impeller repaired by laser cladding in the step (2) by adopting a vacuum heat treatment furnace, wherein the heat treatment process comprises the following steps: tempering at 550 ℃, preserving heat for 120 minutes and air cooling.
(4) And finishing to specified size and precision.
The hardness of the laser cladding functional layer is HRC 58-HRC 60.
The aluminum slurry pump impeller base in the embodiment of the invention is 2Cr 13.
Example 1.
The adopted powder comprises 1.6 percent of C, 21 percent of Mo, 2.2 percent of Si, 15 percent of Cr, 31.5 percent of Co, 0.5 percent of Ti and the balance of Fe and inevitable impurities by weight percentage, and the granularity of each component is-125 to +300 meshes.
Preparing the powder with the granularity of-125 to +300 meshes according to the proportion of the components, placing the powder into a mixer for mixing, and carrying out vacuum drying treatment when in use.
The cladding method is carried out according to the following steps.
(1) The new matrix is added.
And (3) adding an impeller cladding size chart to the preferable 2Cr13 matrix machine, and performing surface nondestructive testing without defects.
(2) And (4) laser cladding.
The impeller preheats 180 ℃, utilizes fiber laser, cooperates the synchronous powder feeding device of laser, adopts fiber laser, and its parameter is: the focal length f of the focusing mirror is 300 mm; the cladding power P is 2600W; the diameter D of the light spot is 3 mm; the cladding scanning speed V is 1000 mm/min; the lapping rate is 50%.
(3) And (6) heat treatment.
Carrying out heat treatment on the aluminum slurry pump impeller repaired by laser cladding in the step (2) by adopting a vacuum heat treatment furnace, wherein the heat treatment process comprises the following steps: tempering at 550 ℃, preserving heat for 120 minutes and air cooling.
(4) And finishing to specified size and precision.
The thickness of the cladding layer is 1.0mm, and the surface hardness is HRC 58.
Carrying out nondestructive flaw detection on the clad impeller surface, wherein the processed part has no defects such as cracks, air holes and the like; the sample piece is placed in a laboratory simulation test field, no steam corrosion pit occurs, and the service life is prolonged by 3 times.
Example 2.
The adopted powder comprises 1.55% of C, 20% of Mo, 2% of Si, 16% of Cr, 30% of Co, 0.7% of Ti, the balance of Fe and inevitable impurities, and the balance of Fe and inevitable impurities by weight percentage, wherein the granularity of each component is-125 to +300 meshes.
The powder preparation was as in example 1.
The cladding method is different from the embodiment 1 in the following points:
the cladding technological parameters are as follows: focusing mirror f is 300mm, laser power P is 2900W, focusing spot diameter: d is 3mm, the scanning speed V is 1200mm/min, the lapping rate T is 50%, the thickness of a cladding layer formed after cladding is 1.2mm, and the surface hardness is HRC 57.5.
Carrying out nondestructive flaw detection on the clad impeller surface, wherein the processed part has no defects such as cracks, air holes and the like; the sample piece is placed in a laboratory simulation test field, no steam corrosion pit occurs, and the service life is prolonged by 3 times.
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