CA2391909C - Aging treatment for ni-cr-mo alloys - Google Patents
Aging treatment for ni-cr-mo alloys Download PDFInfo
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- CA2391909C CA2391909C CA002391909A CA2391909A CA2391909C CA 2391909 C CA2391909 C CA 2391909C CA 002391909 A CA002391909 A CA 002391909A CA 2391909 A CA2391909 A CA 2391909A CA 2391909 C CA2391909 C CA 2391909C
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/10—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of nickel or cobalt or alloys based thereon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
- C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
- C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
- C22C19/051—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W
- C22C19/055—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W with the maximum Cr content being at least 20% but less than 30%
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
- C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
- C22C19/051—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W
- C22C19/056—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W with the maximum Cr content being at least 10% but less than 20%
Abstract
A single step heat treatment for Ni-Cr-Mo alloys containing from 12% to 19% chromium and from 18% to 23% molybdenum provides higher yield strength, high tensile strength and other mechanical properties comparable to those observed in similar alloys age-hardened according to current practices. This treatment is done over a total time of at least 4 hours and preferably less than 50 hours. However, the treatment works for only those alloys having alloying elements present in amounts according to an equation here disclosed.
Description
TITLE
AGING TREATMENT FOR Ni-Cr-Mo ALLOYS
FIELD OF THE INVENTION
The invention relates to heat treatment processes for nickel-chromium molybdenum-alloys having a chromium content of from 12 to 19 weight percent.
BACKGROUND OF THE INVENTION
It is well-known that chromium imparts corrosion resistance to nickel base alloys.
Therefore, Ni-Cr-Mo alloys and particularly those with chromium content of 15 to 24%
have been popular for use in corrosive environments such as encountered in the chemical and petrochemical industries.
Age-hardening is a process used in the metallurgical industry to give an alloy composition higher strength, as measured by its yield strength, tensile strength, and by notched stress rupture tests typically used in the art. Various applications demand a combination of high tensile strength and low thermal expansion properties. One such application is in the aerospace industry. Another application is seal rings used in land-based gas turbines. A combination of high tensile strength and ductility is also very useful for bolts. Because of the demanding operating conditions and performance parameters for metal products in these applications, various methods of age-hardening have been used. One common technique is to heat the alloy to a selected high temperature, hold the alloy at that temperature for a period of time and then cool the alloy to mom temperature. For some alloy compositions, the alloy may be heated to one temperature, cooled, heated again to a second temperature and cooled. Examples of these processes are disclosed in United States Patent No. 3,871,928. The temperatures and time periods used to age harden an alloy depend upon the composition of the alloy.
For all age-hardenable commercial alloys there are established times and temperatures used that have become standard in the industry because they are known to produce the desired properties. For Ni-Cr-Mo alloys having high chromium content, that is chromium greater than 12% , the general view in the art is that heat treatment beyond the initial annealing in an effort to improve mechanical properties would be impractical due to the lengthy required times (hundreds to thousands of hours) and such treatments simply have not been done.
Solid-solution strengthened nickel- chromium-molybdenum (Ni-Cr-Mo) alloys and nickel-molybdenum (Ni-Mo) alloys are widely utilized for commercial applications in the chemical industry, for example. Generally, considered to be single phase materials, discounting the presence of minor carbide phases, alloys such as these are not usually considered responsive to heat treatment, and are therefore used in the annealed condition.
There are exceptions, where some particular alloys do exhibit a commercially exploitable age hardening response. However, in these instances the age-hardening response observed is attributable to other elements, such as niobium, aluminum and titanium being present in the alloy composition. The exception to this is HAYNES~ 242TM alloy which will be discussed later. The fact that Ni-Cr-Mo and Ni-Mo alloys are not commercially age-hardenable does not mean that they do not exhibit any metallurgical response to thermal exposure at intermediate temperatures. Actually, alloys of this type can exhibit complex secondary phase reactions when exposed in the temperature range from about 538°C to 871 °C. Unfortunately, the phases which form can often be deleterious to both alloy ductility and other aspects of service performance. This is particularly observed with Ni-Mo alloys containing about 25 to 30 % molybdenum. In such materials, exposure at temperatures from about 538°C to 871°C can result in the rapid formation of embrittling Ni3Mo or Ni4Mo phases in the microstructure. This can be a problem for both component manufacturing and for component performance.
For lower molybdenum, higher chromium, content Ni-Cr-Mo alloys with about 16 % molybdenum and 16 % chromium weight percent content, the occurrence of these particular intermetallic phases is not usually observed after short term thermal exposures.
With longer term exposure at temperatures from about 538°C to 694°C, there is a distinctly different metallurgical response. After about 500 to 1000 hours the presence of the phase Ni2(Mo,Cr) is evidenced in the microstructure. A long-range-ordered phase, with structure similar to that of Pt2Mo , the Ni2(Mo,Cr) phase serves to significantly increase the strength of these materials without a severe loss of ductility.
The one major drawback is the prolonged aging time required to produce this phase.
'there are several United States patents that disclose Ni-Cr-Mo alloys. United States Patent No. 4,818,486 discloses a low thermal expansion nickel based alloy that contains 5% to 12% chromium and I O% to 30% molybdenum. The patent teaches that the aging times typically required to obtain desired hardness without deleterious phases being formed is well over 1000 hours at temperatures of 649°C to 816°C far most Ni-Mo-Cr alloys. However, the aging time to harden the alloy composition disclosed in the '486 patent is as little as 24 hours at 649°C. The alloy of this patent has beam marketed under TM TM
the trademarks 242 alloy and HAYNES 242 alloy. HAYNES 242 alloy has been sold for applications requiring high tensile strength and a low coefficient of thermal expansion.
AGING TREATMENT FOR Ni-Cr-Mo ALLOYS
FIELD OF THE INVENTION
The invention relates to heat treatment processes for nickel-chromium molybdenum-alloys having a chromium content of from 12 to 19 weight percent.
BACKGROUND OF THE INVENTION
It is well-known that chromium imparts corrosion resistance to nickel base alloys.
Therefore, Ni-Cr-Mo alloys and particularly those with chromium content of 15 to 24%
have been popular for use in corrosive environments such as encountered in the chemical and petrochemical industries.
Age-hardening is a process used in the metallurgical industry to give an alloy composition higher strength, as measured by its yield strength, tensile strength, and by notched stress rupture tests typically used in the art. Various applications demand a combination of high tensile strength and low thermal expansion properties. One such application is in the aerospace industry. Another application is seal rings used in land-based gas turbines. A combination of high tensile strength and ductility is also very useful for bolts. Because of the demanding operating conditions and performance parameters for metal products in these applications, various methods of age-hardening have been used. One common technique is to heat the alloy to a selected high temperature, hold the alloy at that temperature for a period of time and then cool the alloy to mom temperature. For some alloy compositions, the alloy may be heated to one temperature, cooled, heated again to a second temperature and cooled. Examples of these processes are disclosed in United States Patent No. 3,871,928. The temperatures and time periods used to age harden an alloy depend upon the composition of the alloy.
For all age-hardenable commercial alloys there are established times and temperatures used that have become standard in the industry because they are known to produce the desired properties. For Ni-Cr-Mo alloys having high chromium content, that is chromium greater than 12% , the general view in the art is that heat treatment beyond the initial annealing in an effort to improve mechanical properties would be impractical due to the lengthy required times (hundreds to thousands of hours) and such treatments simply have not been done.
Solid-solution strengthened nickel- chromium-molybdenum (Ni-Cr-Mo) alloys and nickel-molybdenum (Ni-Mo) alloys are widely utilized for commercial applications in the chemical industry, for example. Generally, considered to be single phase materials, discounting the presence of minor carbide phases, alloys such as these are not usually considered responsive to heat treatment, and are therefore used in the annealed condition.
There are exceptions, where some particular alloys do exhibit a commercially exploitable age hardening response. However, in these instances the age-hardening response observed is attributable to other elements, such as niobium, aluminum and titanium being present in the alloy composition. The exception to this is HAYNES~ 242TM alloy which will be discussed later. The fact that Ni-Cr-Mo and Ni-Mo alloys are not commercially age-hardenable does not mean that they do not exhibit any metallurgical response to thermal exposure at intermediate temperatures. Actually, alloys of this type can exhibit complex secondary phase reactions when exposed in the temperature range from about 538°C to 871 °C. Unfortunately, the phases which form can often be deleterious to both alloy ductility and other aspects of service performance. This is particularly observed with Ni-Mo alloys containing about 25 to 30 % molybdenum. In such materials, exposure at temperatures from about 538°C to 871°C can result in the rapid formation of embrittling Ni3Mo or Ni4Mo phases in the microstructure. This can be a problem for both component manufacturing and for component performance.
For lower molybdenum, higher chromium, content Ni-Cr-Mo alloys with about 16 % molybdenum and 16 % chromium weight percent content, the occurrence of these particular intermetallic phases is not usually observed after short term thermal exposures.
With longer term exposure at temperatures from about 538°C to 694°C, there is a distinctly different metallurgical response. After about 500 to 1000 hours the presence of the phase Ni2(Mo,Cr) is evidenced in the microstructure. A long-range-ordered phase, with structure similar to that of Pt2Mo , the Ni2(Mo,Cr) phase serves to significantly increase the strength of these materials without a severe loss of ductility.
The one major drawback is the prolonged aging time required to produce this phase.
'there are several United States patents that disclose Ni-Cr-Mo alloys. United States Patent No. 4,818,486 discloses a low thermal expansion nickel based alloy that contains 5% to 12% chromium and I O% to 30% molybdenum. The patent teaches that the aging times typically required to obtain desired hardness without deleterious phases being formed is well over 1000 hours at temperatures of 649°C to 816°C far most Ni-Mo-Cr alloys. However, the aging time to harden the alloy composition disclosed in the '486 patent is as little as 24 hours at 649°C. The alloy of this patent has beam marketed under TM TM
the trademarks 242 alloy and HAYNES 242 alloy. HAYNES 242 alloy has been sold for applications requiring high tensile strength and a low coefficient of thermal expansion.
Other beneficial properties of the 242 alloy include good thermal stability, good low cycle fatigue resistance, and excellent containment capabilities due to its tensile strength and TM
ductility. HAYNES 242 allay consists of about 8 % (weight percent) chromium, about 20-30 % molybdenum, about 0.35 % to up to about 0.5 % aluminum, up to 0.03 carbon, up to about 0.8 % manganese, up to about 0.8 % silicon, up to about 2 % iron, up to about 1 % cobalt, up to about 0.006 % boron, and the balance weight percent being nickel. r There is a need for a shorter commercially exploitable age hardening process for Ni-Mo-Cr alloys with higher Cr levels (>l2% Cr) than found in U.S. Patent No.
4,818,486 that avoids formation of deleterious Ni3Mo and Ni4Mo phase, as well as mu-phase occurrence.
Another Ni-Cr-Mo alloy is disclosed in United States Patent No. 5,019,184 to Crum et al. That alloy contains 19% to 23% chromium and 14 to 17.5%
molybdenum.
The patent discloses homogenization heat treatment at temperatures ranging from 1149°C
to 1260°C for periods of from 5 to 50 hours. The purpose of the treatment is to produce a corrosion resistant alloy having a desired microstructure rather than to strengthen the alloy. No tensile strength data is given for any of these samples disclosed in the patent.
The alloy of this patent has been commercialized under the designation INCONEL~
alloy 686.
Yet another corrosion resistant Ni-Cr-Ma alloy is disclosed in United States Patent No. 4,906,437 to Heubner et al. This alloy contains 22% to 24% chramium and 15% to 16.5% molybdenum. There is no disclosure of any heat treatment or age -S-hardening of this alloy. The alloy disclosed in this patent has been commercialized under TM
the designation VDM NICROFER 923 h Mo or Alloy S9.
A high yield strength Ni-Cr-Mo alloy is disclosed in United States Patent No.
4,129,464 to Matthews et al. This alloy contains 13% to 18% chromium and 13%
to 18%
molybdenum. The patent says that the alloy could be aged using a single step aging treatment of at least 50 hours at 480°C to S93°C, but all examples are aged 168 hours or more. The statement that at least SO hours is required was an extrapolation of the results obtained from a 168 hours aging treatment. The patent reports data for three alloys numbered 1, 2 and 3. Alloy 1 is commercially available under the trademark TM
HASTELLOY~ C-276 alloy. Alloy 2 is commercially available as HASTELLOY C-4 TM
alloy. Alloy 3 is commercially available as HASTELLOY S alloy.
SUMMARY OF THE INVENTION
We provide a single-step age hardening process for certain nickel-chromium-molybdenum alloys containing from 12% to 19% chromium and from 18% to 23 molybdenum that results in higher yield strength, high tensile strength and comparable other mechanical properties as those observed with the current age-hardening process used in the art, such properties being measured by yield strength, tensile strength, and tensile ductility tests at room temperature. This process works only for those alloys in which the other alloying elements are present in amounts so that the composition has a P
value that is within the range of 31.2 to 35.9 where P is defined by the equation:
P=2.46 AI+0.19Co+0.83Cr-0.16 Cu+0.39 Fe+0.59Mn +1.OMo+0.81Zr+2.lSSi+1.06V+0.39W+0.68Nb + 0.52 Hf + 0.45 Ta + 1.3S Ti The alloys are aged at about 1100° F. to 1325° F. for at least 4 and preferably 48 hours and then air cooled. When so treated the alloys will have tensile properties suitable for use in applications requiring high tensile strength and ductility. By using this relatively short single step aging process high chromium content nickel based alloys having a combination of high yield strength and ductility properties can be made at lower cost than other alloys having such properties. Consequently, the present alloy is a more affordable alloy for applications requiring such properties.
In accordance with one aspect of the present invention there is a nickel-chromium-molybdenum alloy comprised of: from 12% to 19% chromium; from 18% to 23% molybdenum; up to 3% iron; at least one alloying element selected from the group consisting of aluminum, boron, carbon, cerium, cobalt, copper, hafnium, magnesium, manganese, niobium, phosphorous, a rare earth element, silicon, sulfur, tantalum, titanium, tungsten, vanadium and zirconium; and a balance of nickel plus impurities;
wherein the alloy has a P value of from 31.2 to 35.9, P being defined as:
P=2.46A1+0.19Co+0.83Cr-0. l6Cu+0.39Fe+0.59Mn +1.OMo+p,8lZr+2.15Si+1.06V+p.39W+0,68Nb +0.52Hf+0.45Ta+1.35Ti and the alloy is age hardened at about 593°C to about 718°C for at least 4 hours then cooled to room temperature.
DESCRIPTION OF THE FIGURES
FIG. 1 is a graph of the alloys tested based upon the P value and chromium content of the alloy.
FIG. 2 is a graph of the alloys tested based upon the P value and molybdenum content of the alloy.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
We provide a single-step aging treatment for Ni--Cr--Mo alloys containing from 12% to 19% chromium to produce an alloy for applications requiring corrosion resistance, high tensile strength and excellent tensile ductility. This process involves age hardening the - 6a -alloy at about 1100°F. to about 1325°F. for at least 4 hours and then cooling the alloy to room temperature. We have found, however, that this process provides acceptable mechanical properties for only those alloys that contain alloying elements in amounts that provides a P value of from 31.2 to 35.9, P being defined as:
P=2.46A1+0.19Co+0.83Cr-0.16Cu+0.39Fe+p,59Mn+l.OMo+0.81Zr+2.15Si+1.06V+0.
39W+0.68Nb+0.52Hf+0.45Ta+1.35Ti _' We tested 13 nickel base test alloys and 3 Ni-Cr-Mo commercial alloys whose TM
compositions are set forth in Table 1. The commercial alloys were HASTELLOY S
sheet, HASTELLOY C-276 sheet, and HASTELLOY C-4 sheet and plate. The thickness of each sheet was 3.2 mm and the plate was 9.5 mm thick. The designation "n.m." in Table 1 indicates that the presence of an element was not measured. Table 1 also reports the P value for each alloy.
The chromium content of the test alloys ranged from 11.56% for alloy 6 to 22.28% for alloy 10. Molybdenum ranged from 14.73% in alloy 10 to 23.89% in alloy 13. All of the alloys contained similar amounts of aluminum, cobalt, iron, and manganese. Tungsten was present within a range of 0.13% to 0.34%. The alloys also contained small amounts of boron, carbon, cerium, copper, magnesium, phosphorus, sulfur, silicon, and vanadium. The test alloys were annealed after hot rolling to 12.7 mrn plate at annealing temperatures in the range of 1038°C to 1093°C
for thirty minutes and water quenched. The commercial alloys were cut from sheets or plate available from the manufacturer. All of the test alloys were treated with a single-step aging treatment in which they were aged at 649°C for 48 hours. Then they were air cooled to room TM TM
temperature. The commercial alloys HASTELLOY S, HASTELLOY C-276 and HASTELLOY C-4 alloys, were aged at 593°C for 50 hours. Then they were air cooled to room temperature. This 50 hour treatment corresponds to the treatment proposed for those alloys by Matthews et al. in United States Patent No. 4,129,464.
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All of the samples were tested to determine their tensile properties. The tests determined yield strength, ultimate tensile strength, and percent elongation by following the standard ASTM E-8 test procedures for such alloys. The results of those tests are reported in Table 2 Room Temperature Tensile Properties for Sample Alloys (Aged b49°C (1200°F~/48hr/AC) Allo 0.2%'Yield ~~S~e~Te~ile percent y Strength ~ Elongation a ksi a si 1 787 114.2 1282 185.9 41.0 2 802 116.3 1293 187.5 40.5 3 744 107.9 1236 179.3 43.0 4 353 51.2 798 115.7 63.7 390 56.6 807 117.0 59.9 6 347 50.3 830 120.4 63.8 _7 323 46.9 781 113.3 63.7 8 776 112.6 1267 183.7 43.6 9 548 79.5 1055 153.0 50.8 345 50.1 784 113.7 61.7 11 353 51.2 805 116.7 63.2 12 __ 865 125.5 1329 192.7 32.6 13 ~ 892 129.3 1417 205.5 30.0 To be acceptable an alloy must have elongation values greater than 40 percent and yield strengths greater than 500 MPa. Alloys 1, 2, 3, 8 and 9 all had acceptable properties. Alloys 12 and 13 did not possess enough tensile ductility as measured by the percent elongation. Alloys 4, 5, 6, 7, 10 and 11 did not possess a high enough yield strength. Since the chromium content and molybdenum content of alloy 12 is within the range of chromium content and molybdenum content of the acceptable alloys it is clear that neither chromium content nor molybdenum content is the sole predictor of acceptable tensile properties in this class of alloys. We concluded that it is the interaction of nearly all of the alloying elements that is the predictor of such properties. Indeed, we discovered that when the alloy has a P value in the range of 31.2 to 35.9, chromium in the range of 12% to 19% and molybdenum in the range of 18% to 23% were acceptable tensile properties achieved with this aging process.
Figure 1 is a graph of the tested alloys based upon the P value of the alloy and the chromium content. Each alloy that had acceptable tensile properties is plotted with a dot.
An X is used to plot those alloys whose tensile properties were not acceptable after the alloy was subjected to the two-step aging treatment. A box has been drawn around the acceptable alloys. It is readily apparent from Figure 1 that the acceptable alloys have a chromium content of 12% to 19% and a P value within the range of 31.2 to 35.9.
Figure 2 is a graph similar to Figure 1 but plots the P value of the alloy against the molybdenum content. As shown in Figure 2, the acceptable alloys contain from 18% to 23% molybdenum. The fact that Alloy 4 did not pass the tensile property requirements even though its chromium content is within the desired range indicates that molybdenum content is also critical. Alloy 4 had only 17% molybdenum.
Having identified the compositions of alloys that could be successfully age-hardened at 649°C to 48 hours and air cooled we then looked to see if the alloys disclosed by Matthews et al. in United States Patent No. 4,192,464 would have acceptable properties when treated at 593°C for 50 hours. That patent at column 4, lines 4-S contains a statement that the data obtained and there reported for longer treatments suggests that aging for about SO hours at 593°C will be effective. Test samples were cut from TM TM
commercially available HASTELLOY S sheet, HASTELLOY C-276 sheet and TM TM
HASTELLOY C-4 sheet and HASTELLOY C-4 plate. The thickness of the sheets was 3.2 mm and the plate was 9.5 mm thick. The composition of these alloys is in Table 1.
These samples were aged at 593°C for 50 hours and then air cooled. The aged samples were then tested to determine their tensile strength properties using standard test procedures. The results of those tensile tests are reported in Table 3.
Room Temperature Tensile Properties for Commercial Altoys (Aged 593°C (1100°F)/SOhr/AC) 0.2%Yield h rile percent Strength Ul~ S~e T
Alloy ng Elongation -t (MPa) (MPa) (ksi) (ksi) HASTELLOY 455 66.0 923 133.8 46.8 S
C-276 472 68.5 858 124.5 55.2 C-4 plate 401 58.1 865 125.5 55.2 C-4 sheet 652 94.5 1058 153.4 43.9 All of the samples had acceptable tensile strength and elongation. The yield strength of TM
HASTELLOY S sheet, C-276 sheet and C-4 plate samples were below 500 MPa and consequently were unacceptable. The C-4 sheet had acceptable yield strength and unlike the C-4 plate was acceptable. The difference in yield strength between the C-4 sheet and the C-4 plate is likely attributable to some unknown phenomenon, possibly a surface phenomenon, that gives thin specimens higher yield strength than thicker samples.
Whatever the reason for the difference, the test data indicates that, contrary to Matthews' suggestion, a 50 hour aging treatment at 593°C will not produce acceptable results for all Ni-Cr-Mo alloys. Indeed, it only worked for a thin sample of a single alloy.
The present process works for all forms of alloys meeting the chromium, molybdenum and P
value specified here. All of the three commercial alloys had less than 18%
molybdenum.
Furthermore, C-4 alloy and HASTELLOY S alloy had P values below 31.2. As our data demonstrates a single step aging treatment as short as 48 hours provides acceptable tensile properties for ail forms of only those Ni-Cr-Mo alloys having 12% to 19%
chromium, 18% to 23% molybdenum and a P value of from 31.2 to 35.9.
Those skilled in the art will recognize that while chromium and molybdenum must be present within the ranges encompassed by the test specimens, other alloying elements are not so limited. Indeed, those elements could be present in amounts within the ranges set forth in the UNS descriptions for commercially available Ni-Cr-Mo alloys which include those tested here and alloys such as C-200ttK~ alloy, C-22~ alloy, SM
2060 Mo alloy and MAT-21 alloy. More specifically there could be up to 0.5% aluminum, 0.015%
boron, 0.02% carbon, 2.5% cobalt, 2.0% copper, 3.0% iron, 1.5% manganese;
1.25%
niobium, 0.04% phosphorus, 0.03 % sulfur, 0.75% silicon, 2.2% tantalum, 0.7%
titanium, 0.35% vanadium and 4.5% tungsten and 0.1°!° of a rare earth element.
Having now defined the alloys that can benefit from this age hardening process we considered what time and temperature range would be acceptable. A series of aging treatments was given to Alloy 2 and Alloy 8. After the aging treatments were performed the hardness was measured to determine whether the samples had age hardened.
The results are shown in Tables 4 and 5.
Table 4 The Effect of Different Aging Treatments on the Hardness of Alloy 2 Tem Time h Hardness c Una ed --- < 20.0 593C/1100F 48 20.6 649C/1200F 24 31.3 649C/1200F 48 36.1 677C/1250F 48 < 20.0 704C/1300F 48 < 20.0 Table 5 The Effect of Different Aging Treatments on the Hardness of Alloy 8 Tem Time (h) Hardness Rc Una ed --- < 20 593C/1100F 48 20.1 649C/1200F 48 34.3 677C/1250F 2 < 20 677C/1250F 4 27.1 677C/1250F 8 39.9 677C/1250F 12 34.6 677C/1250F 16 35.0 677C/1250F 48 35.8 704C/1300F 8 < 20 704C/1300F 12 < 20 704C/1300F 16 33.1 704C/1300F 48 35.3 718C/1325F 48 28.6 732C/1350F 48 < 20 760C/1400F 48 < 20 A sample was determined to have age hardened if it had a Rockwell C (Rc) hardness value of more than 20Ø A sample in the unaged condition confirmed that the material started out with a hardness of less than 20Ø All samples given aging treatments at 649°C for about 24 to 48 hours were found to strongly age harden.
The samples aged at 593°C for 48 hours just barely hardened. The samples of Alloy 2 aged at 677°C and 704°C for 48 hours did not harden. However, samples of Alloy 8 did age harden when treated at 677°C and 704°C for 48 hours. Indeed, Alloy 8 age hardened when treated at 677°C for times ranging from 4 hours to 48 hours. At 704°C age hardening did not occur in Alloy 8 at 8 or 12 hours, but did occur when the treatment time was 16 and 48 hours.
Furthermore, Alloy 8 age hardened when treated at 718°C for 48 hours.
The difference between the responses of Alloys 2 and 8 to heat treatment times and temperatures can be attributed to the fact that Alloy 8 has higher molybdenum and lower chromium than Alloy 2. The test results indicate that the alloy should be age hardened for at least about 4 hours at a temperature ranging from about 593°C to about 718°C. Even though the longest aging time used in our tests was 48 hours longer aging times could be used.
However, we prefer that the age-hardening treatment here disclosed be done in a total time of less than 100 hours and preferably less than 50 hours. Indeed we prefer to complete the process in 48 hours. By using heat treatments totaling less than 100 hours, and preferably not greater than SO hours, one can produce lower cost, high chromium, Ni-Cr-Mo alloys that have desirable tensile properties. While the process here disclosed may also work when total aging times exceed 100 hours, the energy costs associated with such treatments make the process less desirable and commercially impractical.
This process represents a significant advancement. Prior to the present invention Ni-Cr-Mo alloys having greater that 12% chromium were not produced in the age hardened condition since the required aging times were considered to be too great.
Because of the energy costs associated with such long treatments the estimated cost of a higher chromium, age-hardened alloy was considered too high and no such alloys are in commercial existence. The single-step age-hardening treatment here disclosed will produce lower cost, high chromium, Ni-Cr-Mo alloys that have desirable tensile properties.
Although we have described certain present preferred embodiments of our alloy and method of producing that alloy, it should be distinctly understood that our invention is not limited thereto but may be variously embodied within the scope of the following claims.
ductility. HAYNES 242 allay consists of about 8 % (weight percent) chromium, about 20-30 % molybdenum, about 0.35 % to up to about 0.5 % aluminum, up to 0.03 carbon, up to about 0.8 % manganese, up to about 0.8 % silicon, up to about 2 % iron, up to about 1 % cobalt, up to about 0.006 % boron, and the balance weight percent being nickel. r There is a need for a shorter commercially exploitable age hardening process for Ni-Mo-Cr alloys with higher Cr levels (>l2% Cr) than found in U.S. Patent No.
4,818,486 that avoids formation of deleterious Ni3Mo and Ni4Mo phase, as well as mu-phase occurrence.
Another Ni-Cr-Mo alloy is disclosed in United States Patent No. 5,019,184 to Crum et al. That alloy contains 19% to 23% chromium and 14 to 17.5%
molybdenum.
The patent discloses homogenization heat treatment at temperatures ranging from 1149°C
to 1260°C for periods of from 5 to 50 hours. The purpose of the treatment is to produce a corrosion resistant alloy having a desired microstructure rather than to strengthen the alloy. No tensile strength data is given for any of these samples disclosed in the patent.
The alloy of this patent has been commercialized under the designation INCONEL~
alloy 686.
Yet another corrosion resistant Ni-Cr-Ma alloy is disclosed in United States Patent No. 4,906,437 to Heubner et al. This alloy contains 22% to 24% chramium and 15% to 16.5% molybdenum. There is no disclosure of any heat treatment or age -S-hardening of this alloy. The alloy disclosed in this patent has been commercialized under TM
the designation VDM NICROFER 923 h Mo or Alloy S9.
A high yield strength Ni-Cr-Mo alloy is disclosed in United States Patent No.
4,129,464 to Matthews et al. This alloy contains 13% to 18% chromium and 13%
to 18%
molybdenum. The patent says that the alloy could be aged using a single step aging treatment of at least 50 hours at 480°C to S93°C, but all examples are aged 168 hours or more. The statement that at least SO hours is required was an extrapolation of the results obtained from a 168 hours aging treatment. The patent reports data for three alloys numbered 1, 2 and 3. Alloy 1 is commercially available under the trademark TM
HASTELLOY~ C-276 alloy. Alloy 2 is commercially available as HASTELLOY C-4 TM
alloy. Alloy 3 is commercially available as HASTELLOY S alloy.
SUMMARY OF THE INVENTION
We provide a single-step age hardening process for certain nickel-chromium-molybdenum alloys containing from 12% to 19% chromium and from 18% to 23 molybdenum that results in higher yield strength, high tensile strength and comparable other mechanical properties as those observed with the current age-hardening process used in the art, such properties being measured by yield strength, tensile strength, and tensile ductility tests at room temperature. This process works only for those alloys in which the other alloying elements are present in amounts so that the composition has a P
value that is within the range of 31.2 to 35.9 where P is defined by the equation:
P=2.46 AI+0.19Co+0.83Cr-0.16 Cu+0.39 Fe+0.59Mn +1.OMo+0.81Zr+2.lSSi+1.06V+0.39W+0.68Nb + 0.52 Hf + 0.45 Ta + 1.3S Ti The alloys are aged at about 1100° F. to 1325° F. for at least 4 and preferably 48 hours and then air cooled. When so treated the alloys will have tensile properties suitable for use in applications requiring high tensile strength and ductility. By using this relatively short single step aging process high chromium content nickel based alloys having a combination of high yield strength and ductility properties can be made at lower cost than other alloys having such properties. Consequently, the present alloy is a more affordable alloy for applications requiring such properties.
In accordance with one aspect of the present invention there is a nickel-chromium-molybdenum alloy comprised of: from 12% to 19% chromium; from 18% to 23% molybdenum; up to 3% iron; at least one alloying element selected from the group consisting of aluminum, boron, carbon, cerium, cobalt, copper, hafnium, magnesium, manganese, niobium, phosphorous, a rare earth element, silicon, sulfur, tantalum, titanium, tungsten, vanadium and zirconium; and a balance of nickel plus impurities;
wherein the alloy has a P value of from 31.2 to 35.9, P being defined as:
P=2.46A1+0.19Co+0.83Cr-0. l6Cu+0.39Fe+0.59Mn +1.OMo+p,8lZr+2.15Si+1.06V+p.39W+0,68Nb +0.52Hf+0.45Ta+1.35Ti and the alloy is age hardened at about 593°C to about 718°C for at least 4 hours then cooled to room temperature.
DESCRIPTION OF THE FIGURES
FIG. 1 is a graph of the alloys tested based upon the P value and chromium content of the alloy.
FIG. 2 is a graph of the alloys tested based upon the P value and molybdenum content of the alloy.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
We provide a single-step aging treatment for Ni--Cr--Mo alloys containing from 12% to 19% chromium to produce an alloy for applications requiring corrosion resistance, high tensile strength and excellent tensile ductility. This process involves age hardening the - 6a -alloy at about 1100°F. to about 1325°F. for at least 4 hours and then cooling the alloy to room temperature. We have found, however, that this process provides acceptable mechanical properties for only those alloys that contain alloying elements in amounts that provides a P value of from 31.2 to 35.9, P being defined as:
P=2.46A1+0.19Co+0.83Cr-0.16Cu+0.39Fe+p,59Mn+l.OMo+0.81Zr+2.15Si+1.06V+0.
39W+0.68Nb+0.52Hf+0.45Ta+1.35Ti _' We tested 13 nickel base test alloys and 3 Ni-Cr-Mo commercial alloys whose TM
compositions are set forth in Table 1. The commercial alloys were HASTELLOY S
sheet, HASTELLOY C-276 sheet, and HASTELLOY C-4 sheet and plate. The thickness of each sheet was 3.2 mm and the plate was 9.5 mm thick. The designation "n.m." in Table 1 indicates that the presence of an element was not measured. Table 1 also reports the P value for each alloy.
The chromium content of the test alloys ranged from 11.56% for alloy 6 to 22.28% for alloy 10. Molybdenum ranged from 14.73% in alloy 10 to 23.89% in alloy 13. All of the alloys contained similar amounts of aluminum, cobalt, iron, and manganese. Tungsten was present within a range of 0.13% to 0.34%. The alloys also contained small amounts of boron, carbon, cerium, copper, magnesium, phosphorus, sulfur, silicon, and vanadium. The test alloys were annealed after hot rolling to 12.7 mrn plate at annealing temperatures in the range of 1038°C to 1093°C
for thirty minutes and water quenched. The commercial alloys were cut from sheets or plate available from the manufacturer. All of the test alloys were treated with a single-step aging treatment in which they were aged at 649°C for 48 hours. Then they were air cooled to room TM TM
temperature. The commercial alloys HASTELLOY S, HASTELLOY C-276 and HASTELLOY C-4 alloys, were aged at 593°C for 50 hours. Then they were air cooled to room temperature. This 50 hour treatment corresponds to the treatment proposed for those alloys by Matthews et al. in United States Patent No. 4,129,464.
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All of the samples were tested to determine their tensile properties. The tests determined yield strength, ultimate tensile strength, and percent elongation by following the standard ASTM E-8 test procedures for such alloys. The results of those tests are reported in Table 2 Room Temperature Tensile Properties for Sample Alloys (Aged b49°C (1200°F~/48hr/AC) Allo 0.2%'Yield ~~S~e~Te~ile percent y Strength ~ Elongation a ksi a si 1 787 114.2 1282 185.9 41.0 2 802 116.3 1293 187.5 40.5 3 744 107.9 1236 179.3 43.0 4 353 51.2 798 115.7 63.7 390 56.6 807 117.0 59.9 6 347 50.3 830 120.4 63.8 _7 323 46.9 781 113.3 63.7 8 776 112.6 1267 183.7 43.6 9 548 79.5 1055 153.0 50.8 345 50.1 784 113.7 61.7 11 353 51.2 805 116.7 63.2 12 __ 865 125.5 1329 192.7 32.6 13 ~ 892 129.3 1417 205.5 30.0 To be acceptable an alloy must have elongation values greater than 40 percent and yield strengths greater than 500 MPa. Alloys 1, 2, 3, 8 and 9 all had acceptable properties. Alloys 12 and 13 did not possess enough tensile ductility as measured by the percent elongation. Alloys 4, 5, 6, 7, 10 and 11 did not possess a high enough yield strength. Since the chromium content and molybdenum content of alloy 12 is within the range of chromium content and molybdenum content of the acceptable alloys it is clear that neither chromium content nor molybdenum content is the sole predictor of acceptable tensile properties in this class of alloys. We concluded that it is the interaction of nearly all of the alloying elements that is the predictor of such properties. Indeed, we discovered that when the alloy has a P value in the range of 31.2 to 35.9, chromium in the range of 12% to 19% and molybdenum in the range of 18% to 23% were acceptable tensile properties achieved with this aging process.
Figure 1 is a graph of the tested alloys based upon the P value of the alloy and the chromium content. Each alloy that had acceptable tensile properties is plotted with a dot.
An X is used to plot those alloys whose tensile properties were not acceptable after the alloy was subjected to the two-step aging treatment. A box has been drawn around the acceptable alloys. It is readily apparent from Figure 1 that the acceptable alloys have a chromium content of 12% to 19% and a P value within the range of 31.2 to 35.9.
Figure 2 is a graph similar to Figure 1 but plots the P value of the alloy against the molybdenum content. As shown in Figure 2, the acceptable alloys contain from 18% to 23% molybdenum. The fact that Alloy 4 did not pass the tensile property requirements even though its chromium content is within the desired range indicates that molybdenum content is also critical. Alloy 4 had only 17% molybdenum.
Having identified the compositions of alloys that could be successfully age-hardened at 649°C to 48 hours and air cooled we then looked to see if the alloys disclosed by Matthews et al. in United States Patent No. 4,192,464 would have acceptable properties when treated at 593°C for 50 hours. That patent at column 4, lines 4-S contains a statement that the data obtained and there reported for longer treatments suggests that aging for about SO hours at 593°C will be effective. Test samples were cut from TM TM
commercially available HASTELLOY S sheet, HASTELLOY C-276 sheet and TM TM
HASTELLOY C-4 sheet and HASTELLOY C-4 plate. The thickness of the sheets was 3.2 mm and the plate was 9.5 mm thick. The composition of these alloys is in Table 1.
These samples were aged at 593°C for 50 hours and then air cooled. The aged samples were then tested to determine their tensile strength properties using standard test procedures. The results of those tensile tests are reported in Table 3.
Room Temperature Tensile Properties for Commercial Altoys (Aged 593°C (1100°F)/SOhr/AC) 0.2%Yield h rile percent Strength Ul~ S~e T
Alloy ng Elongation -t (MPa) (MPa) (ksi) (ksi) HASTELLOY 455 66.0 923 133.8 46.8 S
C-276 472 68.5 858 124.5 55.2 C-4 plate 401 58.1 865 125.5 55.2 C-4 sheet 652 94.5 1058 153.4 43.9 All of the samples had acceptable tensile strength and elongation. The yield strength of TM
HASTELLOY S sheet, C-276 sheet and C-4 plate samples were below 500 MPa and consequently were unacceptable. The C-4 sheet had acceptable yield strength and unlike the C-4 plate was acceptable. The difference in yield strength between the C-4 sheet and the C-4 plate is likely attributable to some unknown phenomenon, possibly a surface phenomenon, that gives thin specimens higher yield strength than thicker samples.
Whatever the reason for the difference, the test data indicates that, contrary to Matthews' suggestion, a 50 hour aging treatment at 593°C will not produce acceptable results for all Ni-Cr-Mo alloys. Indeed, it only worked for a thin sample of a single alloy.
The present process works for all forms of alloys meeting the chromium, molybdenum and P
value specified here. All of the three commercial alloys had less than 18%
molybdenum.
Furthermore, C-4 alloy and HASTELLOY S alloy had P values below 31.2. As our data demonstrates a single step aging treatment as short as 48 hours provides acceptable tensile properties for ail forms of only those Ni-Cr-Mo alloys having 12% to 19%
chromium, 18% to 23% molybdenum and a P value of from 31.2 to 35.9.
Those skilled in the art will recognize that while chromium and molybdenum must be present within the ranges encompassed by the test specimens, other alloying elements are not so limited. Indeed, those elements could be present in amounts within the ranges set forth in the UNS descriptions for commercially available Ni-Cr-Mo alloys which include those tested here and alloys such as C-200ttK~ alloy, C-22~ alloy, SM
2060 Mo alloy and MAT-21 alloy. More specifically there could be up to 0.5% aluminum, 0.015%
boron, 0.02% carbon, 2.5% cobalt, 2.0% copper, 3.0% iron, 1.5% manganese;
1.25%
niobium, 0.04% phosphorus, 0.03 % sulfur, 0.75% silicon, 2.2% tantalum, 0.7%
titanium, 0.35% vanadium and 4.5% tungsten and 0.1°!° of a rare earth element.
Having now defined the alloys that can benefit from this age hardening process we considered what time and temperature range would be acceptable. A series of aging treatments was given to Alloy 2 and Alloy 8. After the aging treatments were performed the hardness was measured to determine whether the samples had age hardened.
The results are shown in Tables 4 and 5.
Table 4 The Effect of Different Aging Treatments on the Hardness of Alloy 2 Tem Time h Hardness c Una ed --- < 20.0 593C/1100F 48 20.6 649C/1200F 24 31.3 649C/1200F 48 36.1 677C/1250F 48 < 20.0 704C/1300F 48 < 20.0 Table 5 The Effect of Different Aging Treatments on the Hardness of Alloy 8 Tem Time (h) Hardness Rc Una ed --- < 20 593C/1100F 48 20.1 649C/1200F 48 34.3 677C/1250F 2 < 20 677C/1250F 4 27.1 677C/1250F 8 39.9 677C/1250F 12 34.6 677C/1250F 16 35.0 677C/1250F 48 35.8 704C/1300F 8 < 20 704C/1300F 12 < 20 704C/1300F 16 33.1 704C/1300F 48 35.3 718C/1325F 48 28.6 732C/1350F 48 < 20 760C/1400F 48 < 20 A sample was determined to have age hardened if it had a Rockwell C (Rc) hardness value of more than 20Ø A sample in the unaged condition confirmed that the material started out with a hardness of less than 20Ø All samples given aging treatments at 649°C for about 24 to 48 hours were found to strongly age harden.
The samples aged at 593°C for 48 hours just barely hardened. The samples of Alloy 2 aged at 677°C and 704°C for 48 hours did not harden. However, samples of Alloy 8 did age harden when treated at 677°C and 704°C for 48 hours. Indeed, Alloy 8 age hardened when treated at 677°C for times ranging from 4 hours to 48 hours. At 704°C age hardening did not occur in Alloy 8 at 8 or 12 hours, but did occur when the treatment time was 16 and 48 hours.
Furthermore, Alloy 8 age hardened when treated at 718°C for 48 hours.
The difference between the responses of Alloys 2 and 8 to heat treatment times and temperatures can be attributed to the fact that Alloy 8 has higher molybdenum and lower chromium than Alloy 2. The test results indicate that the alloy should be age hardened for at least about 4 hours at a temperature ranging from about 593°C to about 718°C. Even though the longest aging time used in our tests was 48 hours longer aging times could be used.
However, we prefer that the age-hardening treatment here disclosed be done in a total time of less than 100 hours and preferably less than 50 hours. Indeed we prefer to complete the process in 48 hours. By using heat treatments totaling less than 100 hours, and preferably not greater than SO hours, one can produce lower cost, high chromium, Ni-Cr-Mo alloys that have desirable tensile properties. While the process here disclosed may also work when total aging times exceed 100 hours, the energy costs associated with such treatments make the process less desirable and commercially impractical.
This process represents a significant advancement. Prior to the present invention Ni-Cr-Mo alloys having greater that 12% chromium were not produced in the age hardened condition since the required aging times were considered to be too great.
Because of the energy costs associated with such long treatments the estimated cost of a higher chromium, age-hardened alloy was considered too high and no such alloys are in commercial existence. The single-step age-hardening treatment here disclosed will produce lower cost, high chromium, Ni-Cr-Mo alloys that have desirable tensile properties.
Although we have described certain present preferred embodiments of our alloy and method of producing that alloy, it should be distinctly understood that our invention is not limited thereto but may be variously embodied within the scope of the following claims.
Claims (12)
1. A nickel-chromium-molybdenum alloy comprised of:
from 12% to 19% chromium;
from 18% to 23% molybdenum;
up to 3% iron;
at least one alloying element selected from the group consisting of aluminum, boron, carbon, cerium, cobalt, copper, hafnium, magnesium, manganese, niobium, phosphorous, a rare earth element, silicon, sulfur, tantalum, titanium, tungsten, vanadium and zirconium; and a balance of nickel plus impurities; wherein the alloy has a P value of from 31.2 to 35.9, P being defined as:
P=2.46A1+0.19Co+0.83Cr-0.16Cu+0.39Fe+0.59Mn +1.0Mo+0.81Zr+2.15Si+1.06V+0.39W+0.68Nb+0.52Hf+0.45Ta+1.35Ti and the alloy is age hardened at about 593°C to about 718°C for at least 4 hours then cooled to room temperature.
from 12% to 19% chromium;
from 18% to 23% molybdenum;
up to 3% iron;
at least one alloying element selected from the group consisting of aluminum, boron, carbon, cerium, cobalt, copper, hafnium, magnesium, manganese, niobium, phosphorous, a rare earth element, silicon, sulfur, tantalum, titanium, tungsten, vanadium and zirconium; and a balance of nickel plus impurities; wherein the alloy has a P value of from 31.2 to 35.9, P being defined as:
P=2.46A1+0.19Co+0.83Cr-0.16Cu+0.39Fe+0.59Mn +1.0Mo+0.81Zr+2.15Si+1.06V+0.39W+0.68Nb+0.52Hf+0.45Ta+1.35Ti and the alloy is age hardened at about 593°C to about 718°C for at least 4 hours then cooled to room temperature.
2. The alloy of claim 1, wherein the alloying elements consist of:
up to about 0.5% aluminum;
up to 0.02% carbon;
up to about 1.5% manganese;
up to about 2.5% cobalt;
up to about 4.5% tungsten; and up to about 0.015% boron.
up to about 0.5% aluminum;
up to 0.02% carbon;
up to about 1.5% manganese;
up to about 2.5% cobalt;
up to about 4.5% tungsten; and up to about 0.015% boron.
3. The alloy of claim 1, also comprising:
up to about 0.1 % of a rare earth element;
up to about 2.0% copper;
up to about 1.25% niobium;
up to about 0.04% phosphorus;
up to about 0.75% silicon;
up to about 0.03% sulfur;
up to about 2.2% tantalum;
up to about 0.7% titanium; and up to about 0.035% vanadium.
up to about 0.1 % of a rare earth element;
up to about 2.0% copper;
up to about 1.25% niobium;
up to about 0.04% phosphorus;
up to about 0.75% silicon;
up to about 0.03% sulfur;
up to about 2.2% tantalum;
up to about 0.7% titanium; and up to about 0.035% vanadium.
4. The alloy of claim 1, also comprising at least one of hafnium and tantalum.
5. The alloy of claim 1, wherein the alloy is comprised of:
from 12% to 19% chromium;
from 18% to 23% molybdenum;
from 0.12% to 0.2% aluminum;
from 0.002% to 0.006% carbon;
from 0.30% to 0.34% manganese;
from 1.0% to 1.7% iron;
from 0.05% to 0.8% cobalt;
from 0.10% to 0.34% tungsten; and from 0.002% to 0.005% boron.
from 12% to 19% chromium;
from 18% to 23% molybdenum;
from 0.12% to 0.2% aluminum;
from 0.002% to 0.006% carbon;
from 0.30% to 0.34% manganese;
from 1.0% to 1.7% iron;
from 0.05% to 0.8% cobalt;
from 0.10% to 0.34% tungsten; and from 0.002% to 0.005% boron.
6. The alloy of claim 5, also comprising:
from 0.005% to 0.049% cerium;
from 0.01 % to 0.06% copper;
from 0.001 % to 0.004% magnesium;
from 0.002 to 0.005% phosphorus;
from 0.001 % to 0.004% sulfur; and from 0.01% to 0.02% vanadium.
from 0.005% to 0.049% cerium;
from 0.01 % to 0.06% copper;
from 0.001 % to 0.004% magnesium;
from 0.002 to 0.005% phosphorus;
from 0.001 % to 0.004% sulfur; and from 0.01% to 0.02% vanadium.
7. The alloy of any one of claims 1 to 6, wherein the alloy is age hardened in not more than 50 hours.
8. The alloy of any one of claims 1 to 7, wherein the alloy is age hardened at about 649°C for 48 hours.
9. A method for treating an alloy having a composition comprised of from 12%
to 19% chromium, from 18% to 23% molybdenum, up to about 0.5% aluminum, up to about 0.015% boron, up to 0.02% carbon, up to about 2.5% cobalt, up to about 3% iron up to about 1.5% manganese, up to about 1.25% niobium, up to about 0.75%
silicon, up to about 2.2% tantalum, up to about 0.7% titanium, up to about 4.5% tungsten, and the balance nickel plus impurities, wherein the alloy has a P value of from 31.2 to 35.9, P
being defined as:
P=2.46 Al+0.19 Co+0.83 Cr-0.16Cu+0.39 Fe+0.59 Mn +1.0 Mo+0.81 Zr+2.15 Si+1.06 V+0.39 W+0.68 Nb + 0.52 Hf+0.45 Ta+1.35 Ti the method comprised of:
age hardening the alloy at about 593°C to about 718°C for at least 4 hours; and cooling the alloy to room temperature.
to 19% chromium, from 18% to 23% molybdenum, up to about 0.5% aluminum, up to about 0.015% boron, up to 0.02% carbon, up to about 2.5% cobalt, up to about 3% iron up to about 1.5% manganese, up to about 1.25% niobium, up to about 0.75%
silicon, up to about 2.2% tantalum, up to about 0.7% titanium, up to about 4.5% tungsten, and the balance nickel plus impurities, wherein the alloy has a P value of from 31.2 to 35.9, P
being defined as:
P=2.46 Al+0.19 Co+0.83 Cr-0.16Cu+0.39 Fe+0.59 Mn +1.0 Mo+0.81 Zr+2.15 Si+1.06 V+0.39 W+0.68 Nb + 0.52 Hf+0.45 Ta+1.35 Ti the method comprised of:
age hardening the alloy at about 593°C to about 718°C for at least 4 hours; and cooling the alloy to room temperature.
10. The method of claim 9, wherein the alloy is age hardened in not more than hours.
11. The method of claim 9, wherein the alloy is age hardened at about 649°C for 48 hours.
12. The method of claim 9, wherein the alloy is age hardened in not more than hours.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US09/894,353 US6579388B2 (en) | 2001-06-28 | 2001-06-28 | Aging treatment for Ni-Cr-Mo alloys |
| US09/894,353 | 2001-06-28 | ||
| US10/165,649 | 2002-06-07 | ||
| US10/165,649 US6610155B2 (en) | 2001-06-28 | 2002-06-07 | Aging treatment for Ni-Cr-Mo alloys |
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| Publication Number | Publication Date |
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| CA2391909A1 CA2391909A1 (en) | 2002-12-28 |
| CA2391909C true CA2391909C (en) | 2006-01-10 |
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| Application Number | Title | Priority Date | Filing Date |
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| CA002391909A Expired - Lifetime CA2391909C (en) | 2001-06-28 | 2002-06-27 | Aging treatment for ni-cr-mo alloys |
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| Country | Link |
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| EP (1) | EP1270755B1 (en) |
| JP (1) | JP4977302B2 (en) |
| KR (1) | KR20030003016A (en) |
| CN (1) | CN1249260C (en) |
| AU (1) | AU784826B2 (en) |
| CA (1) | CA2391909C (en) |
| GB (1) | GB2377945B (en) |
| MX (1) | MXPA02006451A (en) |
| TW (1) | TWI226906B (en) |
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| CN101333613B (en) * | 2008-08-06 | 2010-06-09 | 钢铁研究总院 | Nickel-based expansion alloy for metal connector of medium temperature plate type solid-oxide fuel battery |
| CN102108555B (en) * | 2009-12-23 | 2012-08-29 | 中国科学院金属研究所 | High-temperature perfect oxidation resistance type nickel-based single-crystal alloy and preparation method thereof |
| WO2013101561A1 (en) | 2011-12-30 | 2013-07-04 | Scoperta, Inc. | Coating compositions |
| JP5652730B1 (en) * | 2013-03-28 | 2015-01-14 | 日立金属株式会社 | Ni-base superalloy and manufacturing method thereof |
| US9802387B2 (en) | 2013-11-26 | 2017-10-31 | Scoperta, Inc. | Corrosion resistant hardfacing alloy |
| JP5725630B1 (en) * | 2014-02-26 | 2015-05-27 | 日立金属Ｍｍｃスーパーアロイ株式会社 | Ni-base alloy with excellent hot forgeability and corrosion resistance |
| US10173290B2 (en) | 2014-06-09 | 2019-01-08 | Scoperta, Inc. | Crack resistant hardfacing alloys |
| US10329647B2 (en) | 2014-12-16 | 2019-06-25 | Scoperta, Inc. | Tough and wear resistant ferrous alloys containing multiple hardphases |
| JP6999081B2 (en) | 2015-09-04 | 2022-01-18 | エリコン メテコ（ユーエス）インコーポレイテッド | Non-chromium and low chrome wear resistant alloys |
| CN107949653B (en) | 2015-09-08 | 2021-04-13 | 思高博塔公司 | Non-magnetic strong carbide forming alloys for powder manufacture |
| US10954588B2 (en) | 2015-11-10 | 2021-03-23 | Oerlikon Metco (Us) Inc. | Oxidation controlled twin wire arc spray materials |
| US20190040491A1 (en) * | 2016-01-29 | 2019-02-07 | Corning Incorporated | Thermally treated metallic materials and related methods |
| US11279996B2 (en) | 2016-03-22 | 2022-03-22 | Oerlikon Metco (Us) Inc. | Fully readable thermal spray coating |
| DE102016124588A1 (en) * | 2016-12-16 | 2018-06-21 | Vdm Metals International Gmbh | USE OF NICKEL CHROM MOLYBDENE ALLOY |
| CN109252120B (en) * | 2018-09-26 | 2020-12-18 | 中南大学 | Method for uniformly refining GH4169 alloy forging structure |
| US11939646B2 (en) | 2018-10-26 | 2024-03-26 | Oerlikon Metco (Us) Inc. | Corrosion and wear resistant nickel based alloys |
| CN110923512B (en) * | 2019-12-04 | 2020-12-04 | 上海江竑环保科技有限公司 | High-temperature corrosion resistant alloy core, production process and electromagnetic heating rotary kiln |
| CN111172483B (en) * | 2020-01-15 | 2021-05-28 | 焦作大学 | Preparation method of Ni-W alloy baseband with high W content |
| CN113604707A (en) * | 2021-08-11 | 2021-11-05 | 广东省科学院新材料研究所 | Nickel-based high-temperature alloy, and preparation method and application thereof |
| CN114182139B (en) * | 2021-12-10 | 2022-12-02 | 西北工业大学 | Precipitation strengthening nickel-based high-temperature alloy and preparation method thereof |
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| ZA74490B (en) * | 1973-02-06 | 1974-11-27 | Cabot Corp | Nickel-base alloys |
| US4129464A (en) * | 1977-08-24 | 1978-12-12 | Cabot Corporation | High yield strength Ni-Cr-Mo alloys and methods of producing the same |
| US4245698A (en) * | 1978-03-01 | 1981-01-20 | Exxon Research & Engineering Co. | Superalloys having improved resistance to hydrogen embrittlement and methods of producing and using the same |
| JPS5925941A (en) * | 1982-08-02 | 1984-02-10 | Mitsubishi Metal Corp | Cylinder and screw member for injection molding machine and extruder for plastic material and its production |
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| KR20030003017A (en) * | 2001-06-28 | 2003-01-09 | 하이네스인터내셔널인코포레이티드 | TWO STEP AGING TREATMENT FOR Ni-Cr-Mo ALLOYS |
-
2002
- 2002-06-25 KR KR1020020035497A patent/KR20030003016A/en not_active Application Discontinuation
- 2002-06-26 GB GB0214715A patent/GB2377945B/en not_active Expired - Lifetime
- 2002-06-26 EP EP02014217.0A patent/EP1270755B1/en not_active Expired - Lifetime
- 2002-06-26 AU AU50646/02A patent/AU784826B2/en not_active Expired
- 2002-06-27 CN CNB021443882A patent/CN1249260C/en not_active Expired - Lifetime
- 2002-06-27 CA CA002391909A patent/CA2391909C/en not_active Expired - Lifetime
- 2002-06-27 MX MXPA02006451A patent/MXPA02006451A/en active IP Right Grant
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Also Published As
| Publication number | Publication date |
|---|---|
| GB2377945A (en) | 2003-01-29 |
| CA2391909A1 (en) | 2002-12-28 |
| GB0214715D0 (en) | 2002-08-07 |
| KR20030003016A (en) | 2003-01-09 |
| EP1270755A1 (en) | 2003-01-02 |
| JP4977302B2 (en) | 2012-07-18 |
| EP1270755B1 (en) | 2014-03-26 |
| MXPA02006451A (en) | 2005-02-03 |
| JP2003064436A (en) | 2003-03-05 |
| CN1407124A (en) | 2003-04-02 |
| CN1249260C (en) | 2006-04-05 |
| AU784826B2 (en) | 2006-06-29 |
| AU5064602A (en) | 2003-01-02 |
| TWI226906B (en) | 2005-01-21 |
| GB2377945B (en) | 2005-03-30 |
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