阅读说明：本技术 一种激光带状纳米复合强化工艺 (Laser banded nano composite strengthening process ) 是由 汤铁兵 鹿广清 魏振华 王振伟 李威 周雪 刘洪武 侯杰 莫春华 董祯 于 2019-11-15 设计创作，主要内容包括：本发明属于激光强化工艺技术领域,提出了一种激光带状纳米复合强化工艺,采用激光强化处理材料对工件表面进行激光强化处理,使得在工件表面形成强化层。激光强化处理材料包括诱导材料、固溶强化材料和沉积强化材料,诱导材料为石墨烯,固溶强化材料包括Nb碳化物、Mo碳化物和Ca碳化物。沉积强化材料包括Ti碳化物、Si碳化物、W碳化物和Ni碳化物。通过上述技术方案,解决了现有技术中铁路道岔钢轨件易磨损、使用寿命短的问题。(The invention belongs to the technical field of laser strengthening processes, and provides a laser strip-shaped nano composite strengthening process. The laser strengthening treatment material comprises an inducing material, a solid solution strengthening material and a deposition strengthening material, wherein the inducing material is graphene, and the solid solution strengthening material comprises Nb carbide, Mo carbide and Ca carbide. The deposit strengthening material includes Ti carbide, Si carbide, W carbide and Ni carbide. Through above-mentioned technical scheme, the problem that the railroad switch rail spare is easy wearing and tearing, life are short among the prior art has been solved.)

1. The laser banded nano composite strengthening process is characterized in that laser strengthening treatment is carried out on the surface of a workpiece by adopting a laser strengthening treatment material, the laser strengthening treatment material comprises an inducing material, a solid solution strengthening material and a deposition strengthening material, and the inducing material is graphene.

2. The laser ribbon nanocomposite strengthening process of claim 1, wherein the solid solution strengthening material comprises Nb carbides, Mo carbides, and Ca carbides.

3. The laser ribbon nanocomposite strengthening process of claim 2, wherein the deposit strengthening material comprises Ti carbide, Si carbide, W carbide, and Ni carbide.

4. The laser ribbon nanocomposite strengthening process of claim 1, wherein the inducing material is nano-sized, the solid solution strengthening material is micro-sized, and the deposition strengthening material is nano-sized.

5. The laser ribbon nanocomposite strengthening process of claim 3, wherein in the laser strengthening treatment material,

the inducing material comprises 6-12 parts of graphene,

the solid solution strengthening material comprises 0.5-1.0 part of Nb carbide, 2-4 parts of Mo carbide and 1.5-2.5 parts of Ca carbide,

the deposition strengthening material comprises 25-30 parts of Ti carbide, 4-10 parts of Si carbide, 40-47 parts of W carbide and 2-4 parts of Ni carbide.

6. The laser ribbon nanocomposite strengthening process according to claim 1, wherein the laser strengthening treatment specifically comprises the following steps:

s1, adding a laser strengthening treatment material into a blender, uniformly mixing to obtain a solid-liquid mixture, and uniformly spraying the obtained solid-liquid mixture on the surface of a workpiece to form a pre-strengthening material layer;

s2, carrying out laser nano strengthening treatment on the surface of the steel rail piece to form a strengthening layer on the surface of the piece.

7. The laser ribbon nanocomposite strengthening process of claim 6, wherein the blending agent in step S1 is a methylcellulose solution.

8. The laser ribbon nanocomposite strengthening process of claim 6, wherein in the step S2, a semiconductor laser generator is used for laser nanostrengthening treatment, the power is 800-3000W, the scanning spot is 3-5 mm, the strengthening rate is 20-120 mm/S, and the distance between scanning strengthening ribbons is 3-10 mm.

9. The laser ribbon nanocomposite strengthening process of claim 6, wherein the depth of the strengthening layer in step S2 is 0.3-0.6 mm.

10. The laser ribbon nanocomposite strengthening process of claim 6, wherein the workpiece is a railroad switch rail member or a railroad train wheel.

Technical Field

The invention belongs to the technical field of laser strengthening processes, and relates to a laser banded nano composite strengthening process.

Background

The turnout is an important component and key equipment of the railway track and is one of important safety parts in railway transportation. The components of switch rail, wing rail, center rail and guard rail of current railway switch are mainly made of alloy steels of U75V, U71Mn, U20Mn2SiCrNiMo, U26Mn2SiCrNiMo and high manganese steel. During railway operation, turnout components are in service in high-heat, high-cold and humid environments. Through fatigue stress damages such as impact, abrasion, vibration and the like of wheel load, the turnout part generates damages such as corrosion, pitting, stripping and falling block, crack and the like, and even generates serious accidents such as fracture and the like. These problems reduce the service life of the turnout, improve the operation cost and influence the safety of railway transportation.

Disclosure of Invention

The invention provides a laser banded nano composite strengthening process, which solves the problems that a railroad turnout steel rail piece is easy to wear and short in service life in the prior art.

The technical scheme of the invention is realized as follows:

the laser banded nano composite strengthening process is characterized in that laser strengthening treatment is carried out on the surface of a workpiece by adopting a laser strengthening treatment material, the laser strengthening treatment material comprises an inducing material, a solid solution strengthening material and a deposition strengthening material, and the inducing material is graphene.

As a further technical solution, the solid solution strengthening material includes Nb carbide, Mo carbide, and Ca carbide.

As a further technical solution, the deposit strengthening material includes Ti carbide, Si carbide, W carbide, and Ni carbide.

As a further technical scheme, the inducing material is in a nanometer scale, the solid solution strengthening material is in a micrometer scale, and the deposition strengthening material is in a nanometer scale.

As a further technical scheme, in the laser strengthening treatment material, the inducing material comprises 6-12 parts of graphene, the solid solution strengthening material comprises 0.5-1.0 part of Nb carbide, 2-4 parts of Mo carbide and 1.5-2.5 parts of Ca carbide,

the deposition strengthening material comprises 25-30 parts of Ti carbide, 4-10 parts of Si carbide, 40-47 parts of W carbide and 2-4 parts of Ni carbide.

As a further technical solution, the laser strengthening treatment specifically includes the steps of:

s1, adding a laser strengthening treatment material into a blender, uniformly mixing to obtain a solid-liquid mixture, and uniformly spraying the obtained solid-liquid mixture on the surface of a workpiece to form a pre-strengthening material layer;

s2, carrying out laser nano strengthening treatment on the surface of the steel rail piece to form a strengthening layer on the surface of the piece. As a further technical scheme, the blending agent in the step S1 is a methyl cellulose solution.

As a further technical scheme, in the step S2, a semiconductor laser generator is used for laser nano-reinforcement treatment, the power is 800-3000W, the scanning spot phi is 3-phi 5mm, the reinforcement rate is 20-120 mm/S, and the distance between scanning reinforcement belts is 3-10 mm.

As a further technical proposal, the depth of the strengthening layer in the step S2 is 0.3-0.6 mm.

According to a further technical scheme, the workpiece is a railway turnout steel rail piece or a railway train wheel, and the material of the railway train wheel is LG60 steel or CL60 steel.

The working principle and the beneficial effects of the invention are as follows:

1. according to the invention, the laser strengthening treatment material is adopted to carry out laser strengthening treatment on the surface of the workpiece, so that a strengthening layer with the depth of 0.3-0.6 mm is formed on the surface of the workpiece, and the strengthening layer has the characteristics of high hardness, high strength, high wear resistance, high toughness, corrosion resistance, fatigue resistance and the like, so that the defects of cracks, peeling, early fracture and the like can be effectively overcome, the train throughput is obviously improved, the turnout replacement cycle is prolonged, the labor intensity is reduced, the service life of the turnout steel rail piece is prolonged by more than 3 times, and the problems that the turnout steel rail piece is easy to wear and short in service life in the prior art are effectively solved.

2. According to the invention, the nano-scale graphene is used as a laser strengthening inducing material, enters a strengthening layer of a workpiece after laser strengthening treatment, has a locking effect on the microstructure shape of a base material, and plays a role in cutting intragranular micro cracks and dislocations existing in a metal microstructure; meanwhile, tissues and carbides which are not completely converted, including the carbides which participate in strengthening treatment, can form an enclosing mechanism, so that the workpiece subjected to laser graphene nano strengthening treatment stabilizes the tissue stress, and improves the technical indexes of dispersion strengthening, strengthening and toughening and the like.

3. In the invention, micron-sized Nb, Mo and Ca carbides are adopted to participate in solid solution strengthening. In the laser strengthening process, at a certain temperature, the micron-sized carbide enters a metal strengthening layer of a workpiece to be strengthened by laser in a solid solution mode to generate metal microstructure grain distortion, so that the solid solution strengthening effect is generated.

4. In the invention, nano Ti, Si, W and Ni carbides are adopted for deposition strengthening. In the laser strengthening process, after the metal material in the preset layer depth of the workpiece is rapidly heated, the expansion degree of the metal material structure is activated, and the nano carbide is rapidly deposited in the metal material strengthening layer to form uniform high-dispersion distribution. After laser strengthening treatment, the metal chemical composition and microstructure appearance in the strengthening layer of the workpiece surface are improved, and the deposition strengthening effect is achieved.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a metallographic microstructure diagram of a strengthening layer of the present invention observed under a metallographic microscope of 100 times;

FIG. 2 is a metallographic microstructure diagram of the strengthening layer of the present invention observed under a 500-fold metallographic microscope.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.