Alloy powder special for laser-remelted high hardness crackless iron-base alloy

Abstract

The invention belongs to the technical field of alloy material, and relates to an improvement on the prior art, in particular to special alloy powder for laser cladding of high-hardness crack-free iron-based alloy. The formula of the alloy powder comprises the following compositions in weight percentage: 0.3 to 0.5 of C, 1.2 to 2.0 of Si, 0.4 to 1.0 of B, 1.5 to 2.5 of Ni, 1.0 to 1.5 of Cr, 1.0 to 1.5 of Mn, 1.5 to 2.5 of Mo, 0.15 to 0.7 of V, and 0.15 to 0.7 of Nb, the balance being Fe; and the total weight of the compositions is 100 percent. The special alloy powder can obtain the iron-based alloy with large area, large thickness and no crakes for laser cladding without preheating and subsequent heat treatment, has high strength, hardness and wear resistance and good plastic toughness of a cladding layer, and has lower cost compared with most of hot spraying self melting alloy powder and the prior laser cladding special iron-based alloy powder.

Description

technical field [0001] The invention belongs to the technical field of alloy materials, is an improvement on the prior art, and in particular relates to a special alloy powder for laser cladding high-hardness and non-cracking iron-based alloys. Background technique [0002] Compared with traditional surface coating technologies, such as conventional surfacing, flame spray welding and electroplating, laser cladding technology, as a new surface treatment technology, has the advantages of fine grains of cladding layer and firm combination of cladding layer and substrate. , heat-affected zone and small thermal deformation. Its disadvantage is that most of the alloy powders used in laser cladding are self-fluxing alloy powders for thermal spraying, and most of the self-fluxing alloy powders contain high content of boron and silicon, which makes some inclusions in the laser cladding process For example, borosilicate cannot float out of the rapidly solidified molten pool smoothly,...

AI Technical Summary

Problems solved by technology

Its disadvantage is that most of the alloy powders used in laser cladding are self-fluxing alloy powders for thermal spraying, and most of the self-fluxing alloy powders contain high content of boron and silicon, which makes some inclusions in the laser cladding process For example, borosilicate cannot float out of the rapidly solidified molten pool smoothly, resulting in high sensitivity to cracking of the laser cladding layer, especially when the hardness of the laser cladding layer is high.

In recent years, some researchers have obtained some iron-based alloy powders for laser cladding, but these powders still have certain limitations. For example, in order to make the laser cladding layer have high hardness and wear resistance, the carbon content in the powder is too high ( weight%>0.65%) leads to low plasticity and toughness of the laser cladding layer, and the cladding layer is easy to crack when laser cladding a large area and thick iron-based alloy. Another example is to make the laser cladding layer have high plasticity and toughness. Too low carbon content (weight%20%), which significantly increases the cost of the powder, and is likely to increase the cold crack sensitivity of the laser cladding layer

In short, the thermal spray alloy powders currently used in laser cladding and the iron-based alloy powders specially developed for laser cladding in recent years have considerable limitations.