CN114908272A

CN114908272A - Nodular cast iron laser cladding powder

Info

Publication number: CN114908272A
Application number: CN202210646754.9A
Authority: CN
Inventors: 邹斌华; 邹才华
Original assignee: Ningbo Leisu Laser Industry Co ltd
Current assignee: Ningbo Leisu Laser Industry Co ltd
Priority date: 2022-06-08
Filing date: 2022-06-08
Publication date: 2022-08-16
Anticipated expiration: 2042-06-08
Also published as: CN114908272B

Abstract

The invention discloses nodular cast iron laser cladding powder, which comprises 1.3-1.6% of C, 1.0-1.8% of Ni1.1-2.6% of Si, 12.5-13.6% of Cr12, 6.2-7.8% of Fe6, 3.2-3.6% of B, 0.03-0.06% of Nb0.03%, CeO ₂ 0.04‑0.06％、La ₂ O ₃ 0.01-0.03 percent of cobalt-based alloy and the balance of Co, the formula of the cobalt-based alloy is improved in the scheme, the components such as niobium, cerium oxide, lanthanum oxide and the like are increased in a micro-quantitative mode, the distribution ratio of the rest components is optimized, the cost is reduced, and the wear resistance of the cladding layer is greatly improved.

Description

Nodular cast iron laser cladding powder

Technical Field

The invention relates to the technical field of cladding, in particular to nodular cast iron laser cladding powder.

Background

The nodular cast iron has excellent comprehensive mechanical properties such as higher strength and toughness, and the graphite spheres have a lubricating effect, so that the nodular cast iron can be frequently used in occasions with higher requirements on service performance instead of steel, but the nodular cast iron is frequently failed due to abrasion of the surface in a harsh service environment, and the nodular cast iron is mainly repaired by adopting methods such as thermal spraying, surfacing and the like in industrial practice at present so as to prolong the service life of the nodular cast iron. The thermal spraying coating has air holes and microcracks, is mechanically combined with the base material and is easy to peel off in the using process; the overlay welding has large heat input amount, so that the dilution rate of the coating is too high, and the base material is easy to deform and crack. The coating prepared by the laser cladding technology has the advantages of fine and compact structure, high metallurgical bonding strength with the base material, small heat affected zone and thermal deformation of the base material and the like, and has wide application prospect in the field of surface strengthening and repairing of key parts.

The powder applied to the ductile cast iron workpiece to be clad at present comprises iron base, cobalt base and the like, wherein the cobalt base has good performance and is widely applied, and the hardness of a common cobalt base alloy cladding layer is generally more than 2 times of that of a QT600-3 brand matrix. With the development of research, some enterprises aim to further improve the wear resistance of the wear-resistant alloy, for example, when rare earth elements are added, although the hardness of the wear-resistant alloy is improved, the addition amount of the rare earth elements is larger, so that the cost is increased, and improvement is needed.

Disclosure of Invention

In order to solve at least one technical defect, the invention provides the following technical scheme:

the application document discloses nodular cast iron laser cladding powder which comprises 1.3-1.6% of C, 1.0-1.8% of Ni2.1-2.6% of Si, 12.5-13.6% of Cr12, 6.2-7.8% of Fe6, 3.2-3.6% of B, 0.03-0.06% of Nb0.03-0.06% of CeO ₂ 0.04-0.06％、La ₂ O ₃ 0.01-0.03% and the balance of Co.

According to the scheme, the formula of the cobalt-based alloy is improved, the components such as niobium, cerium oxide and lanthanum oxide are increased in a micro-scale mode, the distribution ratio of the rest components is optimized, the cost is reduced, and the wear resistance of the cladding layer is greatly improved.

Further, 1.3 to 1.4 percent of C, 1.5 to 1.6 percent of Ni1.3 to 2.35 percent of Si, 13 to 13.2 percent of Cr, 7.2 to 7.4 percent of Fe7, 3.2 to 3.3 percent of B, 0.04 to 0.045 percent of Nb0.04 to 0.045 percent of CeO ₂ 0.05-0.052％、La ₂ O ₃ 0.01-0.02% and the balance of Co. Under the component proportion, the performance of the cladding layer is further improved.

Further, the particle size of the powder particles is 45-90 μm.

Further, the laser cladding parameters of the cladding powder are as follows: the output power is 2.2-2.4KW, the light spot is 2.5-3.5mm, the scanning speed is 800-950mm/min, and the laser beam large-area scanning overlap ratio is 55%. And the laser cladding parameters are optimized in a targeted manner, and the performance of the cladding layer is improved again.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention improves the formula of the cobalt-based alloy and greatly improves the wear resistance of the cladding layer by using trace rare earth elements.

Detailed Description

The present invention will be further described with reference to the following specific examples.

In the following examples and comparative examples, the matrix is made of nodular cast iron QT600-3, the size is 120mm in diameter, the thickness is 15mm, and the thickness of the cladding layer is 3 mm. The particle size of the powder is 45-60 μm.

The weight percentages of the cladding powder components of the following examples are shown in Table 1 below

TABLE 1

In the above examples and comparative examples, the matrix was pre-treated before the cladding operation, in which an angle grinder removed the oxide scale on the surface of the nodular cast iron workpiece, cleaned with acetone, and dried with a blower. The components in the above table were mixed in a ball mill.

During cladding, the powder is coated on the surface of a workpiece in a preset mode, preheated to 240 ℃, and then laser cladding is carried out.

The cladding parameters of the embodiment are as follows: the output power is 2.3KW, the light spot is 3mm, the scanning speed is 900mm/min, and the laser beam large-area scanning overlapping rate is 55%. The cladding thickness is 3 mm.

Cladding parameters of the comparative examples: the output power is 2.3KW, the light spot is 3mm, the scanning speed is 700mm/min, and the laser beam large-area scanning overlapping rate is 30%. The cladding thickness is 3 mm.

The workpiece prepared as above was tested for properties as shown in the following table:

TABLE 2

	Hardness (HV)
		Example 1	862
Example 2	853
		Example 3	849
Example 4	976
		Example 5	982
Example 6	986
		Comparative example 1	649
Comparative example 2	688

It can be seen that the hardness of the cladding layer in the scheme is improved by about four times of QT600-3, and the hardness value of the cladding layer deviating from the scheme greatly falls.

The structural morphology of the cladding layer is analyzed and found through a scanning electron microscope: in the embodiment, the structure of the cladding layer is obviously refined, the uniformity is improved, the spacing of secondary dendrites is small, and the grains are refined. Cr, Ni, Fe and other elements promote the formation of hard phase, and RE elements are dispersed in the dendritic crystal to raise the hardness.

The cladding layer structure is found to be composed of gamma-Co phase and Cr through X-ray diffraction spectrum ₇ C ₃ Phase, CeO ₂ /La ₂ O ₃ The phase and the NbC are equal in composition, are metastable phases fused with various alloy elements, and reflect to the macroscopic performance of a cladding layer, namely the hardness is greatly improved.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims

1. The ductile cast iron laser cladding powder is characterized by comprising 1.3-1.6% of C, 1.0-1.8% of Ni1.1-2.6% of Si, 12.5-13.6% of Cr12, 6.2-7.8% of Fe6, 3.2-3.6% of B, 0.03-0.06% of Nb0.03-0.06% of CeO ₂ 0.04-0.06％、La ₂ O ₃ 0.01-0.03% and the balance of Co.

2. The laser cladding powder of ductile iron according to claim 1, wherein: 1.3 to 1.4 percent of C, 1.5 to 1.6 percent of Nis, 2.3 to 2.35 percent of Si2, 13 to 13.2 percent of Cr, 7.2 to 7.4 percent of Fes, 3.2 to 3.3 percent of B, 0.04 to 0.045 percent of Nb0.04 to 0.045 percent of CeO ₂ 0.05-0.052％、La ₂ O ₃ 0.01-0.02% and the balance of Co.

3. The laser cladding powder of ductile iron according to claim 1, wherein: the particle size of the powder particles is 45-90 μm.

4. The laser cladding powder of ductile iron according to claim 1, wherein: the laser cladding parameters of the cladding powder are as follows: the output power is 2.2-2.4KW, the light spot is 2.5-3.5mm, the scanning speed is 800-950mm/min, and the laser beam large-area scanning overlap ratio is 55%.