JP2000275093A - Elactic component for precise measuring equipment and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a load and deformation by the load to linear relationship for preventing hysteresis by allowing the alloy of an austenite metal with a specific composition to be subjected to solution treatment and hardening, by applying mechanical stress for generating cold curing on forming, and by performing heat curing. SOLUTION: A raw material is the alloy of an austenite metal containing an interstitial atom, contains ferrite by 2% or less, martensite by 2% or less, and chromium by 11% or more, and has crystal structure with nm structure where transformation is fixed. At least one part of the formation of parts consists of cold working, mechanical surface machining, or their combination, and is subjected to plastic deformation of 10% or more by the depth of 50 μm. Then, the heat curing is made at 480 deg.C or less for five hours or more. The parts thus obtained have superior corrosion resistance, thus eliminating the need for surface treatment such as coating. Also, there are no protection layers, thus eliminating poor influence to elastic characteristics, and achieving easy handling on manufacture and use.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention belongs to the field of application and processing of alloy steels in the manufacture of measuring instruments. The present invention also relates to an elastic component used for a precision instrument, and a method of manufacturing and using the same.

[0002]

BACKGROUND OF THE INVENTION In the manufacture of measuring instruments, certain component elements are subject to strict requirements on their mechanical properties. Representative examples of such elements are flexure guides, flexure joints, flexure pivots used in high precision scale load cells. Alternatively, a force / displacement transducer with sensors associated therewith is an example. In the case of a force / displacement converter, the main challenge is to obtain linearity of the relationship between force and displacement and reproducibility of mechanical characteristics. For all elements within the scope of the present invention, it is a common task to minimize retarded elasticity (pseudoelasticity), creep and mechanical hysteresis. Furthermore, these elements must be corrosion resistant and are preferably non-magnetic.

[0003] Parts of the above-mentioned type used in high-performance precision measuring instruments, for example, high-performance load cells of precision balances, are mainly made of martensitic precipitation hardening stainless steel. Usually, this steel is solution-treated and aged at 450 to 550 ° C. Commercially available stainless steels of this type include, for example, 17-7PH, 17-4PH, 13-8Mo, and the like. These have almost zero creep, but have a problem of large hysteresis. That is, when the load and the removal are continuously performed within a short time, the deformation hardly remains, but the curve when the load increases and the curve when the load decreases in the graph showing the load / displacement do not match. Parts made from this material can vary from batch to batch,
The degree of mechanical hysteresis is 1 × 10 ^{−4 to} 5 × 10 ⁻⁴ , although the degree varies depending on the heat treatment, temperature, and working load applied to the material. This degree of hysteresis can be reduced or partially compensated for by appropriate measures, but cannot be eliminated completely, leaving undesirable effects.

Many solutions have been proposed in the prior art to overcome this adverse effect. The solution is to compensate for purely mathematical errors (US Pat. No. 469,129).
No. 0) or fixed parts for connection (DE-U-29612)
167) and the method of compensating for the design of the sensor, a method of influencing the structure of the lattice or the shape and dimensions of the cell to prevent friction of a special alloy or a Bloch wall (magnetic wall) (JP-A-59126760). , DE-A-4034
629).

However, these solutions have problems such as high cost, poor reproducibility, or adversely affecting certain elastic properties. Another possibility of eliminating hysteresis is to use austenitic steel. However, commercially available austenitic steels are optimized for corrosion resistance and have poor elastic properties. Therefore, it is suitable for manufacturing a spring after cold working, but is not suitable for manufacturing a converter because it is apt to creep. Also, new austenitic steels that can withstand higher yield stress at high temperatures have been developed, but their creep properties are not as satisfactory as the conventional ones. Further, another problem arises in the magnetic properties of steel. In particular, in the case of a balance or a precision measuring instrument for measuring a force or a displacement related to a force, it cannot be ignored that the measured value is affected by a magnetic field. Therefore, it is required that the components of the precision measuring instrument be made non-magnetic.

[0006]

DISCLOSURE OF THE INVENTION Accordingly, it is an object of the present invention to provide a corrosion-resistant, non-magnetic, non-magnetic material in which deformation due to an applied load is linearly related to the load, is almost completely reversible, and does not cause hysteresis. Device is provided.

[0007] The present invention solves this problem by providing an elastic component for use in a measuring instrument in which the component is subjected to mechanical stress. The component according to the invention comprises: a) an alloy of austenitic metal containing interstitial atoms, containing, by total weight, up to 2% of ferrite, up to 2% of martensite, up to 11% of chromium and fixed dislocations. B) The alloy has a crystalline structure with a nanostructure. B) The alloy is subjected to solution treatment and quenching, and then the alloy is used.-A part is formed from the alloy, and at least locally cold hardening is performed. Applying the mechanical stress that occurs. Manufactured in a process that consists of subjecting to thermal curing in the range of 200-700 ° C.

This part is important for use in precision measuring instruments such as scales having high resolution. As such, this component is useful for obtaining measurements in transducers and sensors that use the stress-strain relationship or the load-displacement relationship. It can also be used for pivots, guides, joints, etc.

By using such components, a) a transducer incorporating elastic components for measuring mass, weight, force, torque, angle, displacement, etc., b) a precision measuring instrument incorporating elastic components A motion guide mechanism used c) a coupling element used in precision measuring instruments as an elastic part having a local thin part serving as a line for introducing force d) as an elastic part having a local thin part serving as a rotation axis Provided is a method for manufacturing a pivot element used in a precision measuring instrument.

The elastic component of the present invention is made of an alloy whose structure is an austenitic material, and alloy steel is particularly preferable. The proportion of ferrite and / or martensite is less than 2%, thereby ensuring the non-magnetism of the steel. The chromium content is above 11% by weight, thereby giving the steel the required corrosion resistance. Since the crystalline structure has a nanostructure for fixing dislocations, hysteresis, retarded elasticity, and creep are suppressed to a low level.

[0011] The special crystalline structure is formed by cold hardening performed during molding of parts and aging after molding (thermal curing,
(Precipitation hardening).

The raw material for producing the elastic part according to the method of the present invention is an austenitic stainless alloy containing interstitial atoms, which has been subjected to solution treatment and quenching. The material contains iron or nickel alloys that contain enough chromium, other elements added to increase corrosion resistance, and a sufficient amount of nitrogen or other suitable elements to supply interstitial atoms. Choose from any of From this raw material, parts are manufactured by conventional metalworking techniques. The molding of the part is performed once or in a plurality of steps. The manufacturing process of the part consists, at least in part, of cold working or mechanical surfacing or a combination of both. Such a treatment increases the dislocation density in the treated area and hardens the material. Next, the so-called aging (hereinafter referred to as “thermosetting”) is performed for 200 to 7
When applied to the entire part in a temperature range of 00 ° C., it is useful for fixing dislocations, and has a good effect on elastic properties.

[0013] Particularly useful properties are obtained if a plastic deformation of at least 10% is applied to a depth of at least 50 μm in the forming step. Therefore, when the locally thinned part is subsequently heat-cured, excellent elastic properties can be imparted, as in the case of the coupling element and the pivot element.

Thermal curing is carried out at 480 ° C. or less for more than 5 hours, provided that the treatment time is not too long so as not to unacceptably reduce the corrosion resistance, which has a particularly beneficial effect on the elastic properties.

[0015] Other advantages that can be obtained with individual embodiments of the component are described below.

The elastic parts produced by the method according to the invention are particularly suitable for application in precision measuring instruments. therefore,
It can be used with transducers that rely on a high degree of linearity in the relationship between force and displacement or the relationship between stress and deformation to obtain measurements. Alternatively, the present invention may be used for a motion guide mechanism that limits the free motion to some extent, but does not restrict the motion at all. Alternatively, it is suitable for use as an element of a precision measuring instrument having a locally thin portion as a coupling element for transmitting a force or as a pivot element which is a center of a pivoting operation. In precision balances, such components are used individually or in combination.

The present invention takes the following into consideration in order to obtain a component having desired elastic properties in addition to corrosion resistance and non-magnetic properties. That is, it is known that mechanical hysteresis is mainly caused by the magnetoelastic effect in the crystal structure and the friction caused by the Bloch wall. Hysteresis can be reduced by fixing the Bloch wall. However, this leads to deterioration of creep behavior and deterioration of corrosion resistance, so that it is difficult to adopt this method.

A second possibility is to eliminate the Bloch wall by generating a magnetic field. But,
This approach is also problematic and considerably more costly if one seeks to increase reliability without significantly increasing stray magnetic fields.

A third possibility is to use steel without unnecessary Bloch walls in order to avoid such problems. The steel used in this method is a paramagnetic austenitic stainless steel with very low permeability, which is substantially non-magnetic. However, this type of steel has the disadvantage that it has retarded elasticity and does not have creep resistance. (Delayed elasticity means that when a certain load is applied, the deformation increases with the passage of time, and when the load is removed, it takes the same amount of time to eliminate the deformation. Unlike the creep, irreversible The deformation is about 5 × 10 ^{−4 to} 5 × 10 ⁻² in a few minutes at room temperature. However, even a slight retardation elasticity or creep has a significant meaning as a characteristic of components other than the load cell used in precision measuring equipment such as a high-precision balance.

The elastic part according to the invention is made of a corrosion-resistant austenitic metal alloy, preferably of alloy steel, which is stable up to -20 ° C. and has a high degree of freedom for magnetism and hysteresis. Unfavorable properties related to retardation elasticity and creep have been greatly improved by the unique treatment.

Examples of suitable substrates include commercially available austenitic stainless steels containing nitrogen (eg, “18”).
-18 plus) or similar steels optimized to have desirable properties for a given application. The material can be in a shape suitable for subsequent processing, such as a profiled bar, plank, sheet, etc. The components of the alloy are
17-19% of chromium, the same amount of manganese and nitrogen.
It contains 4 to 0.6%, up to 15% carbon, and contains about 1% molybdenum and less than 2% copper. In some cases, alloy components such as Nb, V, W, Ti, Ta, Zr, Al, and B are further added in a range of 0.05% or more for the purpose of preventing the formation of precipitates and improving corrosion resistance. It may be added.

The above proportions are weight percentages of the total weight, as in the following case. The composition of the austenitic steel may have different components. Importantly, it contains a sufficient amount of chromium to increase corrosion resistance, contains manganese to increase the solubility of nitrogen at high temperatures, the total content of nitrogen and carbon is 0.2% or more, and That is, there is more nitrogen than carbon. It is possible to use a nickel alloy instead of an iron alloy, but it is not very attractive from an economic point of view. Hereinafter, the present invention will be described using an iron alloy as an example.

The stainless steel base material, that is, a material having the same composition and crystal structure as the main part of the magnetic domain, must be completely austenitic. Homogenize the material,
To melt the precipitates, the steel must be heated to 1050-1250 ° C.
Forging, hot rolling, solution treatment of the billet is performed at 1050 to 1150 ° C. for 10 to 60 minutes according to its thickness,
The quenching is preferably performed at a rate of 50 ° C. or more per minute to 500 ° C. or less to avoid a critical temperature around 700 to 900 ° C. where the material may corrode. By this treatment, trace amounts of martensite, ferrite, and chromium / iron / manganese nitride still remaining after cooling the melt can be removed, and corrosion resistance can be maintained.

The workpiece is cut from the extruded material.
Manufactured by conventional processes such as punching, milling and turning. The workpiece is then formed into the final shape of the part through a final forming step that includes at least mechanical surface treatment and / or cold forming. Forming the part from raw materials may be performed in a single step.

For example, FIG. 1 is a plan view of a guide 18 of a parallel movement mechanism for a load receiving portion of a balance. This triangular object has a notch 12 and three fixing holes 15. The entire part may be stamped and formed from sheet steel in a single step. The punching die may be designed so that the flexure pivots 13 are formed in three places in one step. In the next step, the deflection pivot is formed by rolling. A surface treatment such as sandblasting may be added to the final molding step. FIG. 2 shows one section of the thin part. The fixing hole 15 and the flexure pivot 13 are connected to the rest of the guide 18. Of course, the flexure pivot 13 may be manufactured as a separate component and connected to the guide body in any suitable manner. A flexure pivot manufactured as a separate part may be used to perform different functions as a pivoting or connecting element of the scale.

As in the case of forming the flexures in the above example, large working stresses on the material may already have occurred at the time of manufacturing the raw workpiece. An example is the load cell 21 whose side view is shown in FIG.
The load cell is basically a fixing part 2 having a fixing hole 25.
6, a load receiving portion 27 also having a fixing hole 25,
It comprises a parallel guide 28 provided between them. In this example, the narrow connection portion 23 acts as a pivot and at the same time as a spring whose deformation is recorded by the strain gauge 24. The load cell is manufactured from a bar having a square cross section. First, the roughly cut workpiece is stretched by 1 to 2% or more to remove bending, and is plastically deformed. Notch 22 that determines the shape and operation of this part
Are made by drilling or milling. The outer surface, at least the connection part 23, is also machined. The plastic deformation that occurs during mechanical finishing is maximized at the surface and becomes smaller as going deeper. Therefore, the optimization of the conditions is performed with respect to the elastic properties of the surface where the maximum stress occurs when the load cell is used.

By processing the surface, at least 5
Local permanent deformation (preferably greater than 10%) occurs to a depth of 0 μm. The effects of cold forming, including forging, rolling, pressing, deep drawing, bending, etc., often have an effect on the entire cross section of each part of the part. Performing cold hardening increases the dislocation density, thereby increasing the yield stress. Therefore, at least using cold curing,
This is the part of the component that is subjected to the maximum stress during use, that is, the part that is thinned in the embodiment. Since cold-hardening increases the dislocation density, the diffusion of atoms, particularly the diffusion of interstitial atoms, during the subsequent high-temperature aging is facilitated.

In the heat treatment performed at the end of the manufacturing process, the finished product is precipitated and hardened, so that the elastic properties are improved, especially the retarded elasticity is reduced, and the creep is substantially zero. However, in this case, it is a problem to avoid a decrease in corrosion resistance.

FIG. 4 shows the limits of thermosetting in a graph of temperature versus time. The upper temperature limit 41 is 700 ° C.
If the upper limit is exceeded, generation of coarse precipitates in a short time cannot be suppressed. At temperatures below the upper limit, the process is controllable. In the range close to the upper limit, the diffusion of chromium is easy because considerable high temperatures promote nitride formation. Therefore, if the treatment time is too long, chromium is deposited around the precipitate, and the chromium content of the base material in the peripheral region is reduced to less than 11%, so that the chromium is easily corroded. Therefore, it is important that the transition is made in accordance with the reciprocal temperature-time curve 42. If the coordinates indicating the processing temperature and processing time are above and to the right of this curve, respectively, then the corrosion resistance is not guaranteed. However, the values indicated by the limit curve 42 and the temperature axis and the time axis are only representative values, not absolute limits, since the position of the coordinates and the shape of the curve are determined by the composition of each material. The constant limit 43 of the flow rate is about 2
Below 00 ° C., little diffusion occurs in any practical time frame, and no further significant structural changes occur. Therefore, in order to prevent the chromium concentration variation from increasing, the thermosetting step is performed at 700
The reaction is carried out at a temperature in the range of 200 to 200 ° C., preferably at 480 ° C. or lower for 5 hours or more.

In any case, if the treatment is continued until the length of the treatment time exceeds the optimum value in the actually used time / temperature range, the elastic properties can be improved accordingly. The higher the processing temperature, the shorter the processing time. In general, a longer time at a lower temperature can provide better results than a shorter time at a higher temperature. If the heat treatment time is too long for a given temperature, larger precipitates will form in the structure,
Due to the large distance between the precipitates, dislocations having high mobility occur when stress is applied. This adversely affects the desired mechanical properties.

The following example shows what particular effect can be obtained by using the method optimized by the process according to the invention. The materials used are DIN specification 1.38
16 standard alloy steel, ie about 20 manganese
%, About 20% chromium, less than 0.12% carbon, 0.4% nitrogen
Austenitic steel containing ~ 0.7%,
After solution treatment at 0 ° C. for 45 minutes, it was quenched with water.

This material is then worked into a shape suitable for storage and transport, but the cold working causes a 5% deformation.
That is, the material is permanently extended 5% in one direction. Then, when the workpiece is milled and drilled, 10% plastic deformation occurs to a depth of at least 50 μm from the surface. Applying a load that produces a stress of 250 MPa for half an hour to such a material results in a retardation of 450-1500 ppm, i.e., the strain of the material is up to 0.15% from the straight line.
Will shift. Hysteresis is 1600-4700
ppm, which means that when the applied load is increased stepwise quickly to 125 Mpa, then to 250 Mpa, and conversely, to 125 Mpa, and further reduced to 0 Mpa, the load value increases and decreases to the same strain value at 125 Mpa. Mean up to 0.47% difference. On the other hand, if the thermosetting is performed at 345 ° C. for 20 hours after molding, the effect of remarkably reducing the delayed elasticity to 150 to 180 ppm and the hysteresis to 140 to 220 ppm can be obtained. If the maximum value of the stress is set to 125 Mpa or less using the molded part for the intended purpose, the retardation elasticity is set to 130 ppm or less and the hysteresis is set to 9 or less.
Each can be suppressed to 5 ppm or less.

Therefore, it is possible to obtain desired and special characteristics of parts by going through two steps of quenching at room temperature and thermosetting. Of these, the latter process is not usually performed in the art because of the problem of a corresponding decrease in corrosion resistance. However, as already seen, this problem only occurs when the steel is aged for an excessively long time, especially near the upper end of the allowed temperature range. This problem can be ameliorated if the content of nitrogen with respect to carbon is sufficient. It is left to a person skilled in the art how to select an appropriate cold working step in accordance with the final heat treatment in order to optimize the result according to the conditions according to the type of alloy and the shape of the material.

The improvement in elastic properties is a consequence of the dislocation-fixed nanostructure. The expression "nanostructure" as used herein is based on the microstructure of crystalline materials, for example, which is described in detail in the following documents. "Physical Metallurgy" by Cahn RW and Haasen P. 1
996 4th edition Elsevier Science BV, Amsterdam, vol.1, chapter 9
.

The structure is based on the type, structure, number, shape and topographical configuration of the phase and / or lattice disturbances.
Depending on the graphical arrangement, such phases and gratings are often not part of the structure in thermodynamic equilibrium. The nanostructure has a polycrystalline matrix (m
atrix) and at least one component finely dispersed in the matrix. The crystals can also be seen at the grain boundaries etched as polished sections. The size and average distance of the finely dispersed components are expressed in nanometers. That is, these are 1-10
In the range of 00 nanometers.

The following finely diffused components are distinguished from each other. Ceramic and / or intermetallic precipitates, interstitial atoms such as carbon and nitrogen deposited around dislocations, the so-called Suzuki cloud, elution and spinod
There are differences between different types of phases, in the form of zones where the concentration of chemical components changes, such as al separations or diffusion gradients. Dislocations, i.e., linear irregular states that occur in the lattice,
It is unique to a polycrystalline base material, and when this material is subjected to stress, dislocations in the crystal structure are likely to move irreversibly. However, if the component is finely dispersed, dislocation movement is prevented, and irreversible displacement of dislocation is prevented at a stress level of at least one-fourth of the yield stress that may exceed 1.0 GPa (140000 psi). Is done. Further, when the thermosetting process is performed at a high temperature, complex intermetallic precipitates such as a so-called Laves phase are generated.

FIG. 5 shows that dislocations 51 extending mainly between large precipitates 52 or phases o having different crystal structures.
cclusion nanostructure 5 consisting of component gradients, Suzuki cloud, and / or precipitates in the nanometer range 5
FIG. 3 is a schematic diagram showing how fixing is performed by No. 3; FIG. 6 schematically shows the Suzuki cloud 61 at the dislocation 62. The atomic layer 63 breaks at the dislocation 62, and the other atomic layers 64 change in the same manner, and return to the normal pattern only at a distance from the dislocation 62.
There is room for interstitial atoms to enter near the dislocation 62 where the crystal lattice is disturbed. These occlusions form the Suzuki cloud 61.

Because of the high chromium content, the parts made by the above process have excellent corrosion resistance.
It easily passes the standard salt spray test. This is an essential and highly advantageous feature for using this part in many industries, especially in the food, feed, chemical and pharmaceutical fields. In addition, the fact that the permeability is kept to a minimum due to the small content of ferrite / martensite means that
This is an indispensable feature when this part is used for precision force measuring equipment. The striking elastic properties are very small retardant elasticity, with creep at a measurable level and virtually zero hysteresis.

When interstitial atoms are included, the matrix is strengthened and the stability of the crystal structure is enhanced. Suitable elements as interstitial atoms are firstly nitrogen and then carbon. However, in addition to these, it can be said that elements having an atomic number of 3 to 7, such as boron, beryllium, and lithium, are also suitable. If the component contains at least 0.2% of interstitial atoms, the enhancement is significant. It is preferable that the content of interstitial atoms is set to be higher than nitrogen and to be 0.4% in total of nitrogen and carbon. Nitrogen is one of the factors that have a decisive effect on the formation of precipitates in the heat treatment process,
It provides better conditions for the formation of nanostructures in the curing process. A high manganese content helps a relatively high proportion of nitrogen to bind.

If additional carbide-forming elements, carbonitride-forming elements and nitride-forming elements are present in an amount of 0.05% or more of the starting material, the grains will grow during the solution treatment. And has an effect of suppressing the formation of a nano-structure.
Also, the level of the yield stress is increased to increase the final strength. As the carbide forming element, niobium or vanadium or a combination of both is preferable. It can also be said that titanium, tantalum, tungsten, and zircon are preferable.
For example, titanium is TiN, TiC, Ti _x (CN)
Form compounds such as _y .

Parts made by containing carbide-forming elements, carbonitride-forming elements and nitride-forming elements individually or in combination have an optimized nanostructure, in particular the effect of stabilizing the dislocation anchoring. 1 shows a crystal structure including a Suzuki cloud having the same. The quenching at room temperature or the final heat treatment at a low temperature for a relatively long time can prevent the nanostructure from becoming coarse.

The copper content of the manufactured part is 0.05%
With the above, advantages other than those described above are obtained. Copper slows the formation of martensite under cold working stress when it reaches a level that causes plastic deformation. Copper also reduces the solubility of nitrogen and promotes nitride precipitation during thermal curing at relatively low temperatures. Copper also contributes to the formation of complex intermetallic and Laves phases at higher ripening temperatures. Copper also improves corrosion resistance by passivation.

Using the method described above, when the austenitic steel is non-magnetic, the ferrite and / or martensite content, and thus the magnetic permeability, can be kept so low that there is almost no lower limit. Therefore, a part manufactured by the method of the present invention has a magnetic field strength of 80 A / c.
The relative magnetic permeability at m can be suppressed to 1.004 or less. This is a specification normally required for non-magnetic metal products.

When the local extremely strong permanent deformation due to cold working reaches 10% or more, the content of ferrite and / or martensite increases at the cold worked part,
An undesired side effect of an increase in the magnetic permeability may occur along with this. However, if the nitrogen content is sufficient, the high content of manganese and some copper help, and this effect hardly appears. Also, the creep properties are significantly improved. By subjecting the manufactured parts to strong deformations up to a depth of at least 50 μm, excellent mechanical properties can be imparted, in particular to the thin parts of the parts, without compromising the general properties aimed at.

The elastic part having the above excellent characteristics can be used for a transducer for measuring mass, weight, force, torque, angle, length and the like. That is, it can be used whenever the transducer uses a linear and reproducible, non-hysteretic relationship between stress and strain in a component to obtain an analog value of the measurand. Such components include, inter alia, load cells with electrostatic or piezoelectric sensors, strain gauges, resonators or similar devices. At room temperature, 10 ppm accuracy can be obtained for stress levels above 0.3 GPa (42000 psi).

As a further application, the component according to the invention is used for mechanical movement guidance devices provided with precision measuring instruments, such as, for example, a parallel movement mechanism of an analytical balance. Resilient components are also particularly suitable for use as thinner parts of precision measuring instruments as connecting or pivoting members.

FIG. 7 shows the operating principle of the electromagnetic force compensation type analytical balance. The balance 71 has a parallelogram-shaped coupling mechanism for guiding the load receiving portion 72, and a parallel guide 78 forming this device has a flexible pivot 73 at one end connected to the stationary console 76, the other end connected to the hanger 77, respectively. Connected through. Since the flex pivot 73 is resistant to warping and buckling, the hanger can only move vertically. When a load is placed on the load receiving portion 72, the load is transferred from the protrusion 81 of the hanger 77 via the tension joint 75 to the fulcrum shaft 83.
Buffer lever 7 rotatably supported by console 76 at
It reaches 9 The tension joint 75 has a connecting element 82, which is a thin part that reliably transmits a one-dimensional force in the vertical direction. The reduced force on the lever 79 is compensated by an electromagnetic force compensator 74 mounted on the console 76. All parts of the scales described above may be manufactured with elastic elements according to the invention. It is particularly preferable to use the elastic element of the present invention for each of the deflection pivot 73, the connecting element 82, and the fulcrum shaft element 83. It is also advantageous to design the entire parallel motion coupling mechanism with the guide 78 and the entire joint 87 and lever 79 as a single elastic part made of one and the same material, combining these elements individually or in combination. It is.

These parts do not require coating or other surface treatments because of their high corrosion resistance. In addition, since there is no protective layer, it is possible to eliminate adverse effects on elastic properties, and it is easy to handle during manufacture and use.

[Brief description of the drawings]

FIG. 1 is a plan view of a parallel motion guide mechanism having a deflection pivot.

FIG. 2 is a sectional view of a principal part of a deflection pivot.

FIG. 3 is a side view of a load cell.

FIG. 4 is a graph of temperature versus time showing the limits of thermosetting.

FIG. 5 is a view showing dislocations that have been fixed.

FIG. 6 is a diagram showing a Suzuki cloud in transposition

FIG. 7 is a diagram showing a basic structure of an analytical balance.

[Explanation of symbols]

 73 pivot 77 hanger 78 guide 82 connecting element 83 fulcrum element

 ──────────────────────────────────────────────────の Continued on the front page (71) Applicant 591079948 CH-8606 Greifensee Shweiz

Claims (20)

[Claims] 1. An elastic part for a measuring instrument subjected to mechanical stress, comprising an alloy of austenitic metal containing interstitial atoms, based on the total weight of ferrite, 2% or less, martensite 2% or less, chromium 11% or more. And an elastic part having a crystalline structure having a nanostructure in which dislocations are fixed. 2. The component according to claim 1, which contains at least 0.2% of the total weight of interstitial atoms having atomic numbers 3 to 7. 3. The component according to claim 2, wherein the total content of nitrogen and carbon is at least 0.4% of the total weight, and the nitrogen content is higher than carbon. 4. The component according to claim 2, comprising at least 0.05% of the total weight of at least one additional element selected from the group consisting of carbides, carbonitrides, and nitrides. 5. The component of claim 4, wherein said at least one additional element is selected from niobium and vanadium. 6. The component according to claim 2, wherein the crystalline structure comprises a Suzuki cloud in the nanometer range. 7. Nitride, carbide, in the nanometer range.
The component according to claim 2, wherein the carbonitride is contained in the crystalline structure. 8. The component according to claim 1, further comprising at least 0.2% of copper by weight. 9. The component according to claim 1, wherein the content of ferrite and martensite is extremely small, and the relative magnetic permeability when the magnetic field strength is 80 A / cm is 1.004 or less. 10. The component of claim 1, wherein the component is cold-worked and includes a portion that has undergone at least a local deformation of at least 10% from its surface to a depth of 50 μm at least locally. 11. The component according to claim 1, which is used for a measuring transducer of a precision measuring instrument. 12. The component according to claim 1, wherein the component is used for a mechanical motion guiding device of a precision measuring instrument. 13. The component according to claim 1, which has a thin portion for transmitting force and is used as a connecting element of a precision measuring instrument. 14. The component according to claim 1, which has a thin portion serving as a rotary moving portion, and is used for a pivot element of a precision measuring instrument. 15. The precision measuring device is a balance.
15. The component according to any one of 14. 16. A corrosion-resistant austenitic alloy containing interstitial atoms which has been subjected to solution treatment and quenching.
14. A method of manufacturing a part according to any of the preceding claims, comprising: molding the part with said alloy, applying mechanical stress causing cold hardening at least locally; A method comprising the step of performing a cure. 17. The method of claim 16, wherein the forming step causes at least a local deformation of at least 10% of any part of the part to a depth of 50 μm from the surface. 18. The method according to claim 16, wherein the heat curing is performed at a temperature of 480 ° C. or less for 5 hours or more. 19. The alloy is a nitrogen-containing chromium-manganese steel,
17. The method of claim 16, wherein the heat curing is performed at about 345 [deg.] C for about 20 hours. 20. The alloy contains at least 0.2% of the total weight of interstitial atoms of atomic numbers 3 to 7, preferably at least 0.4% of the total weight by adding the contents of nitrogen and carbon, 17. The method of claim 16, wherein nitrogen is greater than carbon.