CN104018031B - A kind of alloy material for mechanical device - Google Patents

Abstract

The invention relates to an alloy for mechanical devices. The composition and mass percentage of the alloy are: 20-25% Fe, 14-18% Cr, 1.5%-2.0% Al, 0.7%-1.5% Al Ti, 0.4~1.0% Zr, 0.1~5.0% Nb, less than 0.01% B, less than 0.8% Y, and the balance is Ni.

Description

A kind of alloy material for mechanical device

technical field

The invention belongs to the technical field of metal materials and metallurgy, and in particular relates to an alloy for mechanical devices and a preparation method thereof.

Background technique

Iron-based amorphous alloy strips exhibit excellent soft magnetic properties including: low magnetic loss under AC excitation; enabling applications such as transformers, motors, generators, energy management equipment (which includes pulsed Power generators) and magnetic sensors and other energy-efficient magnetic devices (energyefficientmagneticdevice). In these devices, ferromagnetic materials with high saturation induction and high thermal stability are preferred. Also, in large-scale industrial applications, the ease of manufacture of materials as well as their raw material cost are important factors. Alloys based on amorphous Fe-B-Si meet these requirements mentioned above. However, the saturation induction of these amorphous alloys is smaller than that of crystalline silicon steel (crystalline silicon steel) traditionally used in devices such as transformers, which in part leads to the larger size of devices based on amorphous alloys . Thus, various efforts have been made to develop amorphous ferromagnetic alloys having higher saturation induction. One approach is to increase the iron content in Fe-based amorphous alloys. However, this is not straightforward because the thermal stability of such alloys decreases with increasing Fe content. To alleviate this problem, elements such as Sn, S, C, and P have been added. For example, U.S. Patent No. 5,456,770 (referred to as the '770 patent) discloses amorphous Fe-Si-B-C-Sn alloys in which the addition of Sn increases the formability of such alloys and their saturation induction strength. In US Patent No. 6,416,879 (referred to as the '879 patent) the addition of P to an amorphous Fe-Si-B-C-P system is disclosed, with increasing Fe content to increase the saturation induction. However, the addition of elements such as Sn, S, and C in Fe-Si-B-based amorphous alloys reduces the ductility of cast strips, which makes it difficult to manufacture wide strips. Furthermore, the addition of P to Fe-Si-B-C based alloys, as disclosed in the '879 patent, results in a loss of long-term thermal stability, which in turn causes core losses to increase by tens of percent over several years. Thus, the amorphous alloys disclosed in the '770 and '879 patents have not actually been produced by casting from their molten state.

In addition to the high saturation induction required in magnetic devices such as transformers and inductors, high BH squareness ratio (B- _{Hsquarenessratio} ) and low coercive force Hc are also desirable, where B and H are the magnetic induction intensity and the exciting magnetic field, respectively. The reason is that this type of magnetic material has a high degree of magnetic softness,

That is, it means easy magnetization. This results in low magnetic losses in magnetic devices using these magnetic materials. With awareness of these factors, the inventors of the present application found that by selecting the Si:C ratio at a certain level in an amorphous Fe-Si-B-C system as described in U.S. Patent No. 7,425,239, The C deposition layer on the surface of the strip is maintained at a certain thickness, thereby achieving these desired magnetic properties in addition to high strip ductility. Moreover, in Japanese Patent Publication No. 2009052064, an amorphous alloy strip with high saturation induction was proposed, and the strip was controlled by adding Cr and Mn to the alloy system to control the height of the C deposition layer, whereby the strip exhibited Improved thermal stability of up to 150 years with equipment operating at 150°C. However, the manufactured strip exhibits many protrusions on the strip surface facing the moving chillbody surface. The basic arrangement of the casting nozzle, the cooling body surface on the rotating wheel and the resulting cast strip is illustrated in US Patent No. 4,142,571.

Thus, there is a need for ferromagnetic amorphous alloy ribbons that exhibit high saturation induction, low core loss, high BH square ratio, high mechanical ductility, high long-term thermal stability, and A reduced number of protrusions on the strip surface with a high level of strip manufacturability is the object of the present invention. More specifically, through a comprehensive study of the surface quality of the cast strip during casting, it has been found that when the protrusion height exceeds four times the thickness of the strip or when at 1.5 When the number of protrusions within the m length range is greater than 10, casting has to be terminated in order to meet the condition of packing factor PF>82% (this is the minimum PF required in the industry). In general, the height and number of protrusions increase with casting time. For conventional amorphous alloy strips with a saturation induction B _s of less than 1.6 T, the number of protrusions is increased to 10 before the protrusion height exceeds four times the strip thickness or within every 1.5 m length of the cast strip. Previously, the strip casting time was about 500 minutes. For amorphous alloy strip with Bs > _1.6T , the casting time is typically reduced to about 120 minutes, which results in a casting termination rate of 25%. Therefore, there is a clear need to elucidate the cause of protrusion formation and control it, which is another aspect of the present invention.

Therefore, adding alloying elements to strengthen the alloy is a simple, effective, economical and practical method to increase the strength of the alloy. At present, adding a large amount of alloying elements to improve the strength is the most common method in the development of alloys for mechanical devices. Among the various alloying elements that improve the performance of the alloy, the strengthening effect is the best when multiple rare earth elements are used in combination. At present, the development of alloys for mechanical devices generally contains two or more rare earth elements. In addition, rare earth elements have the functions of purification, degassing and slagging in casting alloys, which can effectively reduce the influence of gases, oxides and harmful elements. At the same time, some rare earth elements can refine the alloy structure or diffuse into the matrix to strengthen the mechanical properties of the alloy. They can also form rare earth compounds in the metal, and these compounds are produced at the grain boundaries of the alloy matrix.

Segregation increases the density of dislocations and increases the degree of lattice distortion, so as to achieve the purpose of strengthening. Although the addition of a large amount of rare earth elements can greatly increase the strength of the alloy, the price of the alloy material is relatively high, and the large-scale application of high rare earth alloys is limited. Therefore, it is of great significance to develop alloys for mechanical devices that do not contain rare earth elements or contain a small amount of rare earth elements.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides an alloy for mechanical devices and a preparation method thereof. The process method is low in cost, simple and easy to implement, and the obtained alloy has higher strength, so that this type of alloy has a higher strength than traditional commercial alloys. Superior mechanical properties.

The invention provides an alloy for a mechanical device, each component and its mass percentage are: 20-25% Fe, 14-18% Cr, 1.5%-2.0% Al, 0.7%-1.5% Ti, 0.4~1.0% Zr, 0.1~5.0% Nb, less than 0.01% B, less than 0.8% Y, and the balance is Ni.

A method for preparing an alloy for a mechanical device provided by the invention mainly includes the following steps:

Take 20~25% Fe, 14~18% Cr, 1.5%~2.0% Al, 0.7%~1.5% Ti, 0.4~1.0% Zr, 0.1~5.0% Nb by weight percentage, less than 0.01 % of B, less than 0.8% of Y, and the balance is Ni added to the vacuum induction furnace for melting and casting into a master alloy ingot, wherein B is added in the form of boric acid, and Y is added in the form of yttrium oxide;

Step 2: Homogenize the master alloy ingot at 1150-1200°C for 20-40 hours;

Step 3: heat deforming the homogenized master alloy ingot at 1000-1150°C;

Step 4: The hot-deformed alloy is subjected to solution treatment at 950-1150°C for 1-4 hours and then air-cooled,

Then carry out aging treatment at 650-850° C. for 10-24 hours and then air-cool to obtain the alloy of the present invention.

Compared with prior art, the beneficial effect of the present invention is:

(1) Compared with other alloys for mechanical devices, the alloy for mechanical devices of the present invention has fewer rare earth elements, and the raw materials used are easy to obtain, low in cost, high in cost performance, and easy for large-scale production.

(2) The process of the present invention is simple, and the equipment used is conventional general-purpose equipment, which is easy to transplant and operate, and has low cost, which can obviously improve the problem of wear resistance and corrosion resistance of the alloy, and can solve the problem that the application of the alloy is limited due to its non-wear resistance and corrosion resistance , can also expand the application field of the alloy.

(3) The tensile properties of the alloy provided by the present invention at room temperature are: the tensile strength Rm is 1810-1909 MPa, and the yield strength Rp0.2 is 1690-1790 MPa.

detailed description

The present invention is further illustrated below by way of examples. It should be understood that the embodiments of the present invention are used to illustrate the present invention rather than limit the present invention. The simple improvements made to the present invention according to the essence of the present invention all belong to the protection scope of the present invention.

According to the national standard GB/T228-2002, various alloy materials obtained in this example were tested for mechanical properties at room temperature and for corrosion resistance.

Example 1:

Take 20% Fe by weight, 16% Cr, 1.5% Al, 1.2% Ti, 0.8% Zr, 3.0% Nb, 0.005% B (added in the form of boric acid), 0.6% Y (added in the form of yttrium oxide), and the balance is that Ni is added to the vacuum induction furnace for smelting and casting into master alloy ingots;

Step 2: Homogenize the master alloy ingot at 1150°C for 30 hours;

Step 3: hot deforming the homogenized master alloy ingot at 1000°C;

Step 4: The hot-deformed alloy is subjected to solution treatment at 950°C for 4 hours and then air-cooled,

Then carry out aging treatment at 850° C. for 15 hours and air-cool to obtain the alloy of the present invention.

Example 2:

Take 25% Fe by weight, 18% Cr, 1.5% Al, 1.0% Ti, 0.6% Zr, 4.0% Nb, 0.006% B (added in the form of boric acid), 0.1% Y (added in the form of yttrium oxide), and the balance is that Ni is added to the vacuum induction furnace for smelting and casting into master alloy ingots;

Step 2: Homogenize the master alloy ingot at 1200°C for 25 hours;

Step 3: hot deforming the homogenized master alloy ingot at 1150°C;

Step 4: The hot-deformed alloy is subjected to solution treatment at 1000°C for 3 hours and then air-cooled,

Then carry out aging treatment at 800° C. for 12 hours and air-cool to obtain the alloy of the present invention.

The mechanical property (according to GB/T228-2002 standard) and the corrosion rate of the gained alloy of the present invention are shown in the following table:

No. Tensile strength Rm(Mpa) Yield strength Rp0.2(Mpa) Corrosion rate in 50% sulfuric acid solution at 70℃ (mg/cm ² h) Example 1 1900 1785 0.02 Example 2 1868 1710 0.03

Claims (1)

1. An alloy for a mechanical device, characterized in that each component and its mass percent in the alloy are: 20% Fe, 16% Cr, 1.5% Al, 1.2% Ti, 0.8% Zr, 3.0% Nb, 0.005% of B, 0.6% of Y, the balance is Ni.