TW568955B - Free-machining Fe-Ni-Co alloy - Google Patents

Abstract

An iron-nickel-cobalt alloy is described which has the following weight percent composition: carbon 0.04 max.; manganese 0.50 max.; silicon 0.20 max.; sulfur 0.020 max.; cobalt 16-18; nickel 28-31; boron 0.020 max. The alloy also contains 0.01-0.50% of an element selected from the group consisting of bismuth, lead, selenium, and combinations thereof. The balance of the alloy is essentially iron and the usual impurities. The alloy according to this invention provides a unique combination of machinability, low thermal expansion, phase stability, and hot workability.

Description

568955 A7 B7 V. Description of the invention (1) Scope of the invention The present invention relates to Fe-Ni-Co alloys that provide controlled thermal expansion, and particularly to such alloys that also provide machinability, processability, thermal expansion and glass sealing performance. BACKGROUND OF THE INVENTION The alloys sold by Carpenter Technology Corporation under the registered trademark KOVAR are Fe-Ni-Co alloys with the following nominal composition (weight percent). Stone inversion up to 0.02% Manganese 0.30% Silicon 0.20% Nickel 29.00% Cobalt 17.00% Iron The rest of the KOVAR alloy provides a low thermal expansion coefficient (COE), which extends over a wider temperature range than the INVAR alloy (36 Ni-Fe) provides COE . This is mainly due to the presence of cobalt in KOVAR alloys. KOVAR alloy COE is almost the same as many hard glass and ceramics such as borosilicate glass, 91-99% opaque alumina, optical fiber and beryllium oxide. KOVAR alloys are used in applications requiring metal-to-glass ^ and metal-to-ceramic sealing. This alloy is also used in a variety of other devices, including fiber optic packaging, mobile phone components, projector lenses and / or light source frames. Laser device and microwave tube frame and ceramic multilayer semiconductor component welding and sealing cover. For many of these zero -4- this paper size applies Chinese National Standard (CNS) A4 specifications (210 X 297 mm) 568955 A7 B7 V. Description of the invention (2

More than 90% of the main KOVAR material will be removed when machining parts. The K 0 V A R alloy is basically a Vostian iron structure and is characterized by a strong work hardening behavior. It has been found that commercial grade alloys, when used in large-scale machining operations, leave what is required due to the strong work hardening characteristics. Machined from a known grade of KOVAR alloy to be viscous and not easily broken. This causes undue wear of the machining tools. It has also been found that workpieces of K0Var alloys will tend to be machined due to the use of higher cutting forces to maintain acceptable production rates. As a result of these problems, precise parts with similar dimensional tolerances cannot be easily machined from a known grade of KOVAR alloy. — Attempts have been made to improve the machinability of KOVAR alloys by including a small amount of sulfur in the alloy. However, in practice, it has been found that more than about 0.015% has an adverse effect on the hot workability of the alloy. When sulfur in KOVAR alloys is limited to less than 0.015%, it has been found to be less important for machinability. Summary of the invention The need for truly easy-to-machine Fe-Ni-Co alloys (such as KOVAR alloys) is solved to the basic extent from alloys according to the invention. The alloy of the present invention is a low thermal expansion Fe-Ni-Co alloy containing a small amount of bismuth to improve the machining performance of the alloy. The alloy according to the present invention has a broad and preferred composition expressed below in weight percent. Widely sewn carbon up to 0.04 up to 0.010 Sewn up to 0.50 0.35-0.45 Silicon up to 0.20 0.08-0.15 -5- This paper size is applicable to China National Standard (CNS) A4 specification (21 × x 297 mm) 568955 A7 B7 V. Description of the invention (3) Sulfur up to 0.20 up to 0.004 Cobalt 16-18 16.8-17.75 Nickel 28-31 28.8-29.6 0.01-0.50 0.08-0.25 up to 0.020 up to 0.018 The rest of the alloy is basically iron and commercial grade Fe-Ni in similar uses -General impurities found in -Co alloys. The foregoing table serves as a convenient summary and is not intended to limit the range of individual elements of the alloys of the present invention used in combination with one another, or to limit the range of elements used in combination with one another. As such, one or more ranges of elements of the broad composition and one or more other ranges of the remaining elements in the preferred composition may be used. In addition, the minimum or maximum value of an element of a preferred embodiment and the maximum or minimum value of this element of another preferred embodiment may be used. Throughout the specification, "percent" or the symbol "%" means weight percent unless otherwise specified. The drawings briefly describe the foregoing outline and the following detailed description of the preferred embodiments of the present invention will be easier to understand when read together with the drawings, in which: Figure 1 is obtained from the working examples of alloys A, B and processed alloys 1 to 6 Photographs of mechanically processed strips; Figure 2 is a sample photo of Example Alloy 1; _ Figure 3 is a graph showing the energy dispersion spectrum of the sample in Figure 2; and Figure 4 is a glass / metal using a metal substrate formed from Example 7 of the present invention Photo of the seal test set. Detailed description -6- This paper size applies to China National Standard (CNS) A4 (210X 297 mm)

Binding

568955 A7 B7 V. Description of the invention (4) A maximum of about 0.50% of manganese is present in the alloy of the present invention as a main deoxidizer. Manganese is also beneficial to the stability of Vostian iron in this alloy and makes the alloy resistant to Asada loose iron metamorphosis (even at lower temperatures). Manganese forms manganese sulfide with available sulfur to contribute to the superior machinability of this alloy. The alloy preferably contains at least about 0.35%. However, the existence of too much vulcanization (especially at the grain boundary) has an adverse effect on the workability of the alloy, especially its hot workability. Too much fierceness also adversely affects the COE of this alloy. For these reasons, manganese is preferably limited to no more than about 0.45%. Up to about 0.04% of carbon is also present in the alloy as a deoxidizer. Carbon also contributes to the stability of Vostian Iron in this alloy. However, it is better to limit the carbon to no more than about 0.010% because too much carbon has an adverse effect on the COE of this alloy. Up to about 0.20% of silicon is present in this alloy by deoxidizing additions when melting and refining the alloy. The alloy preferably contains at least about 0.08% silicon. Too much silicon adversely affects the phase stability of the alloy. Therefore, it is better to limit silicon to no more than about 0.15%. This alloy has at least about 28% nickel, and preferably at least about 28.8%, because nickel contributes the low COE provided by this alloy. Although nickel is beneficial to the stability of the Vostian iron structure, too much nickel results in a high COE that is not suitable for some applications. Therefore, the limit is preferably no more than about 31% and preferably no more than about 29.6% in the alloy. For best results, the alloy contains about 29.4% nickel. Cobalt, like nickel, contributes the low COE of this alloy. Cobalt also extends the operating temperature range of the alloy, as it increases the alloy's house temperature (Tc). Therefore, the alloy contains at least about 16% cobalt and preferably at least about 16.8%. Too much cobalt causes COE to become too high for some uses. Therefore, the cobalt is limited to not more than about 18% in the alloy, and this paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm)

Binding

568955 A7 _______ B7 V. Description of the invention (5) It is better not to exceed about 17.75〇 / 0. For best results, the alloy contains about 17.5 percent aunt. A small amount of sulfur (up to about 0.020%, preferably up to about 0.015%) may be present in this alloy to combine with the shell and form a sulfur that is beneficial to the machining properties of the alloy. For this purpose, the alloy contains at least about 0 008% sulfur and preferably at least about 0.010%. Breaking has an adverse effect on the hot workability of the alloy and excessive amounts will cause thermal cracking during forging or hot rolling. Therefore, when optimal thermal processing performance is required, sulfur is limited to not more than about G GG4% in the alloy, and more preferably to not more than about 0.003%. A small but effective amount of up to about 0.50%, preferably up to about 0.25%) exists in alloys due to mechanical reading f, especially in the machining operations of rotating and forming tools. For this purpose, the alloy preferably contains at least about 0.01% wire, and more preferably at least about 0.08%. For best results, the alloy contains about 0.1 to 0.20% bismuth. The presence of dispersed fine particles in the alloy 'typically has a main dimension of about 1 micron. Xianxian sulphur has the advantage of being good for machining performance. The insoluble secret particles are fine and homogeneous. They are concentrated in grain boundaries. Therefore 'it does not embrittle the alloy even when it melts at the hot working temperature. This phenomenon contrasts most of the manganese sulfide content of high-alloy alloys (such as KOVAR alloys) distributed in "longitudinal streets" extending along grain boundaries. At forging and hot rolling temperatures, vulcanization is postponed and thus weakens the grain-boundary. This method causes thermal cracking when the alloy is hot-worked. It has a lower point and serves as a lubricant for cutting tools when the alloy is subjected to high-speed machining operations. $ Not only significantly increases the life of the cutting tool, but also alleviates the need to use a larger force on the cutting tool. -8-This paper is applicable in the standard s @ 家 standard (CNS) ^ 格 (21 () > < 297 Public love $ ^ ----— 568955 ~. A7 _____ B7 V. Description of invention (6). The most important. The existence of bismuth in the alloy. Other properties of the KOVAR alloy such as low COO and Woer Tian Tie's stability has an adverse effect. Xiaoli's lead (mostly about 05%, but preferably not more than 05%) may exist in this alloy. There are alloys that are used for certain purposes in consideration of toxicity. Workability. In order to understand the advantages of machinability, the alloy contains at least about 0.01% lead and preferably at least about 0.08%. However, because of its toxicity, lead is not preferred and limited for this alloy. In the alloy, it is preferably not more than 0.001%, and more preferably not more than about 0.005%. A small amount of selenium (up to about 0.50%, preferably up to about 0.25%) can also be present in this alloy. For mechanical processing properties. For this purpose, the alloy contains at least about 0.010% selenium and preferably at least about 0.008%. Selenium is not preferred because if there is too much, the alloy becomes susceptible to thermal cracking during hot rolling during forging. Therefore, when it is important for thermal cracking, selenium is limited to not more than about 0.001% and not more than about 0.005% in the alloy. Preferably, bismuth, lead, and selenium can be individually or in combination in the alloy. In this way, the alloy can contain about 0.01-0.50% of bismuth, lead, and selenium, and preferably about 008.025%. As noted above, Bismuth is preferred for enhancing the easy machining ability of this alloy. When bismuth is used as an easy machining additive in the alloy, the lead and selenium in the alloy are each limited to not more than about · 0.01%, and not more than about 0.005% is also better. Similarly, when lead is used as an easy machining additive in the alloy, the bismuth and selenium in the alloy are each limited to not more than about 0.01%, and more preferably to not more than about 005%. When selenium is used as an easy machining additive in the alloy, the lead and bismuth in the alloy are each limited to not more than about 0.01%, and more preferably not more than about 0.005%. A small amount of boron (up to about 0.020%, It is better to be up to about 0.018%) -9- This paper size applies Chinese National Standard (CNS) Α4 Specifications (210 × 297 male I) 568955 A7 B7 V. Description of the invention (7) The alloy has beneficial hot workability. The rest of the alloy is iron and commercial grade Fe-Ni & Fe-N i for similar purposes -General impurities found in C 〇 alloys. No proprietary technology is required to make the alloys of the present invention. The alloy is preferably formed by vacuum induction melting and casting into ingots. Vacuum melting is preferred because it provides strong stirring to the molten alloy, causing Bismuth particles that are distributed substantially uniformly when the alloy is solidified. This alloy is' easy to be hot-worked and / or cold-worked to the required shape and cross-sectional dimensions. The alloy is preferably hot-worked at a temperature of about 1900 ° F, and more preferably at a temperature of about 850-1900QF. The alloy billet is ground and polished before hot rolling to reduce edge cracking. The Fe-Ni-Co alloy according to the present invention can be processed into forms such as rods, plates, cotton, rods, and bars. This alloy can be easily machined into glass-to-metal and ceramic-to-metal seals in electronic tubes, integrated circuits, and other precision parts for electronic devices and other electronic devices. This alloy is also useful for optical fiber packaging, mobile phone components, lens and / or light source frames for projectors, laser devices and microwave tube frames, fusion seal caps for ceramic multilayer semiconductor packages and other devices. The alloy according to the invention provides the following thermal expansion coefficients, which are measured according to the method described in ASTM E228:

COE

25-400 ° C 4.6-5.5 x 10'6 / ° C

25-450 ° C 4.9-5.7 x 10 * 6 / ° C The change point of the alloy is about 400-45 0 ° C. The alloy has a Vostian iron structure at room temperature, and some of it can be transformed into Asada San at a very low temperature (such as -8 (TC or lower) -10- This paper size applies to China National Standard (CNS) A4 specifications (210 X (297 mm)

Binding

568955 A7 ~ B7 V. Description of the invention (8) Iron. The stability of Vostian iron phase is affected by the composition and processing of the alloy. When used in the form of products having a cross-sectional area larger than a bar (such as a rod or rod), the composition may be less uniform. Nonetheless, it is expected that the alloy will not provide a noticeable metamorphosis of Asada loose iron when tested at a cross-section of a test sample with a minimum size greater than 0.5 "at a depth of 80 ° £ for at least 4 hours. Therefore, the easily machined Fe -Ni-Co alloy can be used in applications that require larger cross-section parts (such as the minimum size of 20.5 inches). The Fe-Ni-Co alloy of the present invention provides superior machining performance than known grades of KOVAR alloy. The heavy-duty bar products made from this alloy are also expected to provide improved punching characteristics. Working examples: Vacuum induction melting (VIM) and casting into ingots to make 11 experimental heat-treated parts. Alloys 丨 -6, A And B were prepared from small (32 lb) heat treated parts. Alloys C and D were obtained from commercially available Fe-Ni-Co alloys. Alloy 7 was prepared from 400 lb heat treated parts. Chemical analysis of the test alloys is listed in the table below I. All values are weight percentages. For heat treated parts with Bi, bismuth pellets (3-8 mm diameter) are added to the melt before. The ingot is hot forged to a thickness of about 0.5-0.75 ". -11-This paper size applies Chinese National Standard (CNS) A4 specification (210 X 297 mm) 568955 A7 B7 V. Description of invention (9) P002 P4 P1 0.§ 0015 001 29foPol Pol 17.52 004 002 001 0013 008 00005 0.001 0.39 008 0005 pool 001 29.46 PI 009 17/71 003 002 001 Pol P25 00005 003 001 poo 0.3 ”poil pop 000 0 · 0: 30. {-0: poi 17b 0 · 0: Ob: 00} 0.0: P2: 000 : 00: 0.0: • G \ 0.0005 0.03 0.01 0.15 0.001 0.39 0.09 0.005 0.001 0.01 29.62 0.1 0.09 17.42 0.03 0.03 0.01 0.006 in ο Ρ Ρ Ρ b b U) ο ο ο OJ Η- I— 〇 Ροοο ^ 3〇0 ^ οΡΡο 〇Ρ | 2SS ^ S-b22 | g ^ S as 0.002 0.4 0.1 0.005 0.001 0.01 29.41 0.01 0.01 17.49 0.02 0.01 0.01 0.012 0.14 0.0005 0.03 0.01 0.0005 PPP ^ PP ^ oPggoPg 222 ^ 22〇S§§— > 0.0005 0.001 0.24 0.1 0.005 0.01 0.01 29.13 0.01 0.01 17.53 0.01 0.01 0.01 w 0.0006 0.03 0.01 0.005 0.25 0.12 0.005 0.01 0.03 29.85 i 0.02 0.05 17.02 0.01 0.01 0.01 0.006 ο ο ο P 22 | 0.005 0.43 0.11 0.002 0.002 0.07 30.1 0.02 0.04 17.82 0.024 0.08 0.008 ο -12-

This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 568955 A7 B7 V. Description of the invention (10) The heat-treated products 1-7 represent specific embodiments of the alloy according to the present invention. Heat treatment A is an example of a known grade of KOVAR alloy. Heat treatment B is basically the same as heat treatment A. But it contains a small amount of added sulfur. Heat treatments C and D are comparative examples of other commercially available grades of Fe-Ni-Co alloys. The forging properties of the qualitatively graded alloys A, B and 1 to 7 are stated in Table II. All ingots were preheated at 2100QF before forging. It also shows the qualitative classification of Hot Rolling of Alloy 7 at preheating temperatures of 21001, 2'000 ° F, and 1900 ° F, respectively.

A_II

Forging hot rolling preheating temperature / 2100 ° F / 2h 2100 ° F / 2h 2000 ° F / h 1.900 ° F / 2h Time Alloy No. A Flat surface B Very small edge crack i Small edge crack 2 3 Very small edge crack Very small Some edges are broken 4 Some edges are broken 5 Some edges are broken _ 6 Obvious edges are broken 7 Very small edges are obvious edges are severe edges Very small edges are broken

-13- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 568955

V. Description of the invention (11) Alloys 2 and 3 are better compositions and show good hot workability. Therefore, the bismuth-bearing Fe-Ni-Co alloy according to the present invention is produced without incurring a significant yield loss during forging or hot rolling. Alloys 1 and 4 show the inverse effect of sulfur on hot workability. Leaded alloy 5 provides acceptable forging properties. The results for Alloy 6 show the inverse effects of too many yards on the hot workability of this alloy. C0E and deformation test samples were cut from the forged pellets of each heat-treated product. The results of the thermal expansion and deformation tests are shown in Table II.

A_LLI

_! _ 2 3 4 5 6 7 ABC ㈣ * _3% 0% 0% 0% 0% 0% 〇% 5% 1% 0% COE 4.75, 4.96 5.34, 5.43 5.41 5.45 5.49 5.47 5.15 4.62 4 76 5.35, 5.09 ( 30-400 () 0C0E 5.17, 5.20 5.57, 5.58 5.44 5.61 5.69 5.57 5.43 4.93 5 02 5.50. 5.30 (30-450 () 0 ·

** Asa loose iron phase (vol.%) Was found after 80 ° C / 4 hours deep cooling. The unit of COE = ppm / ° C. The data in Table III shows that alloys 1-7 provide a better phase than alloys A and B. Stability. Data show that alloys 1-7 provide thermal expansion that is accessible over the temperature range of interest. By comparison, the standard specifications of the iron-nickel-cobalt sealing alloy A S T M F -1 5 detail the following COE: (30-.400 ° C) 4.6-5.2 ppm / uC, (30-450 ° C) 5.1-5.5 ppmrC. Mechanical processing test specimens are prepared from forged pellets of alloys 1-6, A and B. The machinability of each alloy was evaluated using a single-point rotation test. The test piece was rotated on an RTW lathe at 4 丨 5 RPM, with a feed rate of 004 leaves per revolution (ipr), and a cut of 0.100 inches deep. Cut depth of Alloy A test piece reduced to -14-

This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 568955 A7 B7 V. Description of the invention (12) 0.050 inch to prevent the test piece from deforming. Table IV presents the qualitative results of the machining tests.

A_IY Alloy No. Machinability A Very sticky and very poor strip, it is not easy to break. Very poor rough seam surface. B is sticky and thick strip, which is not easy to break or curl. Very poor rough seam surface. Extremely soft material 1 Easier to machine than Alloys A and B. This produces "6" and "9" shaped bars. The rough surface is not good, but it is not necessary to reduce the cutting depth to prevent the sample from bending. 2 Very easy to cut. " 6 " and "9 " are excellent strips. There is no problem in machining from a square to a circle. Polishing of typical surfaces that are easy to machine rough cutting. There are some marks on the surface polishing. After rough cutting Slight abrasion was observed on the cutting tool of the insert. 3 The material is easy to cut. In the first batch of rotating circular samples, excellent "6" and "9" shaped bars. Do the next cut at the same feed rate and cutting speed for the smaller diameter, and the good bar will break after winding for two turns. _Good surface with few cutting marks. Minimal wear was observed on the insert of the cutting tool after rough cutting.

Binding

Line -15- This paper size is in accordance with Chinese National Standard (CNS) A4 specification (210X 297 mm) 568955 A7B7 V. Description of invention (13) 4 In the first batch, it was a good strip. The second batch caused bad strips at a cutting depth of 0.100 inches. The material is sticky and does not curl into "6" and "9" shapes. The bars are pushed onto the cutting tool insert before breaking. In the third batch (0.050 inch cutting depth), a similar form of sheet was produced The next batch will provide some "6" and "9" shapes. However, the bars became sticky after about an inch. Material tearing was observed on the back of the cut. The last batch (0.030 inch cutting depth) produced more wear on the cutting tool insert. The strip does not break into the "6" and "9" shapes. It frequently drops before breaking. When using a 0.050 inch cutting depth, the "6" and "9" shapes are initially obtained, but later become a little bit Or thick flat strips without curl. The material is sticky. In the next batch to the last batch, some strips have the shape of "6" and "9". The last batch produced long strips with good surfaces. Some wear was observed on the cutting tool insert. .6 The first and second batches provide acceptable bars that are easily broken. At a cutting depth of 0.050 blades, curling of the flakes was observed, some with a " 9 " shape. Figure 1 shows a machined strip obtained from each of the comparative alloys and the invention alloy. Known grades of KOVAR alloy ( Alloy A) is not easy to machine and provides long, sticky strips are not suitable. Obvious tool wear and metal bending are in mechanical-16-This paper size applies Chinese National Standard (CNS) A4 specification (210X 297 mm) 568955 A7 B7 Fifth invention description (14) Processed in alloy A. In comparison, alloy B and alloys 1-6 both show improved mechanical processing performance to a greater degree than comparable easily-breakable bars. Alloy B is a resulfided KOVAR alloy Example. However, it is marginally better than Alloy B with some sticky bars. Adding only alloys 2 and 3 shows the best machining performance. Figure 2 shows the example alloy 1 (0.015% S and 0.08% Bi ) Microstructure. Energy Dispersive Spectroscopy (EDS) analysis of Alloy 1 (shown in Figure 3) indicates the presence of two forms of inclusions. One is an elongated manganese sulfide (Mn (Ti), typically about 5 microns or longer). S). Others are isotropic and typically Bismuth particles with a diameter of about 1 micron. Therefore, in the alloy according to the present invention, there is an option to introduce one or two forms of inclusions by adjusting the amounts of manganese, sulfur, and sulfur. To prove the glass sealing ability of the alloy according to the present invention The test was performed on the mechanically processed pellets of the alloy 7 pellets. In this test, the 'test pellets (1 忖 X 3 忖 X 0.2 5 leaves each) were cut from the pellets of Alloy 7. The flat surface was polished and then cleaned with acetone. A strip of double-strength window glass was cleaned with acetone and placed on the polished surface of each metal sheet. The metal / glass combination for this example is shown in Figure 4. The metal / glass combination was in air 205 (TF is heated for 6 minutes, and then cooled to room temperature. The metal / glass combination is visually inspected for the presence of bubbles trapped in the glass caused by melting and re-solidification. The sealing ability of the metal / glass combination is based on a 1 to 5 rating Evaluation, in which level 1 indicates that no bubble is observed and level 5 indicates that a large amount of bubble is observed. The combination shown in Figure 4 is 1-2, which indicates acceptable glass sealing performance. Novel glass has been described Sealing alloy. This alloy provides -17- sheet is lower than the present level of the known Chinese National Standard Scale applicable (CNS) A4 size (210 X 297 mm)

Equipment iy 4 568955 A7 B7 V. Description of the invention (15) Thermal expansion, iron-nickel-cobalt glass sealing alloy (such as KOVAR alloy) has significantly better machining performance. The alloys according to the invention also provide acceptable grades of hot workability, thermal expansion and glass sealing capabilities. As such, the alloys according to the present invention provide a unique combination of properties of iron-nickel-cobalt alloys that are relatively closest to known grades and intended for similar uses. The expression used here is narrative rather than limitation. This type of statement is not intended to exclude any equivalent of the narrative feature or any part thereof. However, it will be recognized that various modifications are possible within the scope of the described invention and the scope of the patent application herein.

Order ·

Line -18- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)

Claims (1)

2. 3. 4. 5. 6. 7. 8. 9. 10. 11. An alloy with controlled thermal expansion, which basically consists of the following weight percentages: · carbon up to 0.04 manganese up to 0.50 silicon up to 0.20 sulfur up to 0.020 chain 16-18 nickel 28-31 boron up to 0.020, ^ 01-0.50% of the element is selected from bismuth, lead, selenium and combinations thereof, and the rest of the alloy is basically iron and general impurities. For example, the alloy of item 1 of the patent scope contains no more than 0.01% lead and no more than 0.01% selenium. For example, the alloy in the scope of patent application No. 2 contains at least 0.0 8% bismuth. For example, the alloy in item 3 of the patent application scope contains no more than 0.25% of bismuth. For example, the alloy in item 1 of the patent application scope contains at least 0.35% of manganese. For example, the alloy of claim 5 of the patent scope contains at least 0.008% sulfur. For example, the alloy in item 1 of the patent application scope contains no more than 0.004% sulfur. For example, the alloy in item 7 of the scope of patent application contains no more than 0.01% lead and no more than 0.01% ishi. For example, the alloy of any one of items 1 to 8 in the patent application range contains no more than 0.25%. For example, the alloy in item 9 of the scope of patent application contains at least 0.08% bismuth. An alloy with controlled thermal expansion, which is basically described by the following weight percentages of the patent application scope: B8 C8 D8 carbon up to 0.01 Mu up to 0.45 silicon up to 0.15 sulfur up to 0.015 cobalt 16.8-17.75 nickel 28.8-29.6 boron up to 0.0 1 8 , 0. 008-0.25% of elements are selected from bismuth, lead, selenium and combinations thereof, and the rest of the alloy is basically iron and general impurities. 12. 13. 14. 15. 16. 17. If the alloy in item 11 of the scope of patent application contains no more than 0.01% lead and no more than 0.01% selenium. For example, the alloy of item 12 in the scope of the patent application contains at least 0.08% of the surface. For example, the alloy in item 13 of the patent scope contains no more than 0.25% of bismuth. For example, the alloy in the scope of patent application No. 11 contains at least 0.35% of manganese. For example, the alloy in the scope of patent application No. 15 contains at least 0.0008% sulfur. For example, the alloy in Item 11 of the patent application park contains no more than 0.004% sulfur. 18. The alloy of item 17 in the scope of patent application, which contains not more than 0.01% lead and not more than 0.01% selenium. 19. The alloy according to any one of the items in the scope of patent application, which contains at least 0. 10% of the surface. 20. An alloy with controlled thermal expansion, which basically consists of the following weight percentages: -2 568955 A8 B8 C8 D8 Patent Application Range 3- Carbon up to 0.01 Photo 0.35- up to 0.45 Silicon 0.08- Up to 0.15 Sulfur up to 0.004 16.8 -17.75 nickel 28.8-29.6 4 must be 0.10-0.20 boron up to 0.018, and the rest is basically iron and general impurities. This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)