II. MARCO TEÓRICO
2.2. Bases teóricas
2.2.2. Tiburón azul (Prionace glauca)
To conclude this discussion of heat resisting alloys, let us briefly summarize the chief characteristics of each RA product.
RA330 The work horse of the furnace industry, because it does more jobs better and for less money. Has enough chromium for good oxidation resistance, enough nickel for good ductility, appropriate silicon to resist absorption of carbon and nitrogen. Almost always preferred for carburizing atmospheres. Withstands a lot of thermal shock, yet has above-average strength at operating temperatures. Can be cut, bent and welded without troubles.
RA333 A superior product that also costs more. The combination of 3% cobalt, 3%
molybdenum and 3% tungsten adds high-temperature strength to a base of 45% nickel, 25%
chromium and 1% silicon. Field installations have proven it has excellent resistance to carburization, thermal fatigue and distortion in quenching applications.
RA 253 MA High strength, excellent oxidation resistance to 2000°F (1093°C).
RA 353 MA Twice the strength of RA330 in the 1800-2200°F (980-1200°C) temperature range. Oxidation resistance approximates that of 601 and RA333, but the melting point of RA 353 MA is about 100°F (56°C) higher. Use for muffles, rotary calciners, coal nozzles.
RA 602 CA The strongest and most oxidation resistant high temperature alloy we offer. An upgrade over 601, and potential alternate to alloys 617 or 230. Most cost-effective above 1900°F.
RA309 Preferred for oxidizing atmospheres under 1900°F (1038°C) where resistance to carburizing or nitriding atmospheres is not necessary. Good resistance to sulfidation.
RA310 Good oxidation resistance beyond 2000°F (1093°C) under mildly cyclic conditions.
Good sulfidation resistance, generally good hot corrosion resistance.
RA600 Lower strength but more ductility. Good oxidation, excellent carburization resistance.
Resists hot chlorine gas to 1000°F (538°C)
RA601 Stronger and more oxidation resistant than RA600, with good carburization resistance.
RA446 Special applications, such as salt bath electrodes, glass molds, copper launders, thermowells, soot blowers, etc., where the hot corrosion resistance of maximum chromium is required. Has the best sulfidation resistance but very, very low strength and ductility.
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Al aluminum Mn manganese
Hardness is measured by Rockwell or Brinell machines. The Rockwell B scale (Rb, HRB) is most common for our alloys, Rockwell C is for heat treated steel. Brinell is usually abbreviated BHN (Brinell Hardness Number) on mill certifications.
Grain size is in ASTM numbers. ASTM 4-7 is about average for RA330. Small numbers (ASTM 0, 2, 3) mean coarse grains. Larger numbers (7, 8, 9) mean finer grain size.
Outokumpu and ThyssenKrupp VDM report grain size in micrometers, µm. ASTM 3 to 8 grain size would be 125 to 22 µm, typical for RA 253 MA.
Disclaimer Clause: The data and information in this printed matter are believed to be reliable.
However, this material is not intended as a substitute for competent professional engineering assistance which is a requisite to any specific application. Rolled Alloys makes no warranty and assumes no legal liability or responsibility for results to be obtained in any particular situation, and shall not be liable for any direct, indirect, special or consequential damages therefrom. This material is subject to revision without prior notice.
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BIBLIOGRAPHY
A. L. Marsh, Electric Resistance Element, U.S. Patent No. 811,859 Feb. 6, 1906
F. A. Fahrenwald, Metals for High Temperature, Chemical and Metallurgical Engineering, Vol. 28, p 680—681, April 26, 1923
F. A. Fahrenwald, Some Principles Underlying the Successful Use of Metals at High Temperatures, Proc. ASTM, Vol. 24, p 310—347, 1924
J. D. Corfield, Heat Resisting Alloys and Their Use in the Steel Plant, Iron and Steel Engineer, p 157—194, April, 1929
W.P. Rees, B.D. Burns, and A.J. Cook, Constitution of Iron-Nickel-Chromium Alloys at 650 to 800C, JISI July, 1949
Charles Emery and Paul Goetcheus, Added Life for Brazing Fixtures, Steel, June 27, 1955 Ralph H. Moeller, High-Nickel Alloys for High-Temperature Springs, SPRINGS Magazine, October 1965, Vol. 4, Number 2
H. S. Avery, Cast Heat-Resistant Alloys for High—Temperature Weldments, WRC Bulletin 143, August, 1969 This is the best discussion of heat resistant alloys ever printed.
Bruce McLeod, Cracking in Type 309 High Temperature Fabrications and How to Combat It, Industrial Heating, September and October 1972
A. Roy, F. A. Hagen, and J. M. Corwin, Performance of Heat—Resistant Alloys in
Emission—Control Systems, SAE Paper No. 740093, Automotive Engineering Congress, Detroit, Michigan February 25—March 1, 1974
James Kelly, Understanding Conditions that Affect Performance of Heat Resisting Alloys, Industrial Heating, March & April, 1979
G. R. Rundell, Evaluation of Heat Resistant Alloys in Composite Fixtures, NACE Paper Number 377, Corrosion 86, March 17—21, 1986
James Kelly, Neutral Salt Pot Alloy Life: Maintenance is the Key, Heat Treating, April, 1990 George Y. Lai, High-Temperature Corrosion of Engineering Alloys, 1990 ASM International Gene Rundell and James McConnell, Oxidation Resistance of Eight Heat-Resistant Alloys at 870o, 980o, 1095o, and 1150oC, Oxidation of Metals, Vol. 36, Nos. 3 / 4, 1991
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James C. Kelly, Heat Resistant Alloy Corrosion—More Problems than Solutions, NACE Paper Number 166, Corrosion 91, March 11—15, 1991
James Hamer and James McConnell, Influence of Composition and Microstructure on Performance of Wrought Heat Resisting Alloys, Industrial Heating, April, 1992
James Kelly, Heat Resistant Alloy Performance, Heat Treating, July 1993
J. C. Kelly and J. D. Wilson, Oxidation Rates of Some Heat Resistant Alloys, Heat – Resistant Materials II, Conf. Proc. Of the 2nd International Conference on Heat-Resistant Materials 11—14 September, 1995, Gatlinburg, Tennessee
John P. Steward, Flame Straightening Technology, 1981 LaSalle, Quebec
James Kelly, Metal dusting in the heat treat industry, Stainless Steel World 1999 Conference, KCI Publishing BV, Zutphen, NL 1999
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HISTORY
Austenitic heat resistant alloys and stainless steels as we know them today were invented by Benno Strauss1 of Friedrich Krupp before World War I. Our 35Ni 19Cr alloy RA330 may trace its roots to Nichrotherm® 4, containing 35% nickel and 13-14% chromium, introduced to Germany in 1910 for high temperature applications1. U.S. patents for Strauss’ alloys were issued on June 25, 1913. What we now call 310 was developed by Adolf Fry, also at Krupp, in 1926. The electrical resistance wire Nichrome®, nominally 80Ni 20Cr, and the European alloy Nimonic® 75, nominal 76Ni 20Cr, would appear to be developments of A. L. Marsh’s U.S. Patent No. 811,859, Feb. 6, 1906, for a 15-25% Cr, balance nickel electrical resistance alloy. Michigan Steel Casting Company initially developed the market for rolled Misco Metal in the heat treating industry.
When Rolled Alloys was founded as an independent company in 1953, this alloy was re-named RA330. In 1958 Rolled Alloys lowered the carbon to 0.08% max and, to maintain the strength, raised chromium to the present 19% Cr. The RA330 silicon range was tightened at that time, to 1.00-1.50%.
In that same year work began at Simonds, in conjunction with Rolled Alloys, on the stronger and more carburization resistant grade, RA333.
All of the ASTM specifications for RA330 were written by Rolled Alloys technical personnel, and shepherded through the committee meetings. In 1975, after several years of creep-rupture and tensile testing, along with Rolled Alloys’ attendance at numerous committee meetings RA330 was approved by AMSE Case 1654-1 for use to 800°F (427°C). A few years later RA330 was approved for use to 1650°F (899°C).
Reference
1. The Sorby Centennial Symposium On The History Of Metallurgy, Volume 27, edited by Cyril Stanley Smith, Cleveland, Ohio October 22-23, 1963
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RA330 and RA333 are registered trademarks of Rolled Alloys, Incorporated 153 MA, 253 MA and 353 MA are registered trademarks of Outokumpu AB 602 CA is a registered trademark of ThyssenKrupp VDM
AL-6XN is a registered trademark of ATI Properties, Inc.
20Cb-3 is a registered trademark of Carpenter Technology Corporation
Haynes, Hastelloy, 214, 239, HR-120 and HR-160 are registered trademarks of Haynes International
Kanthal is a registered trademark of Kanthal AB
Nimonic, Inconel, Incoloy, Monel, MA956 and 800HT are registered trademarks of Special Metals, Incorporated
Refrasil is a registered trademark of SGL Carbon Group, Business Unit Fibers and Composites
René 41 is a registered trademark of Teledyne Industries Incorporated Stellite is a a registered trademark of Deloro Stellite, Incorporated
MO-RE, 22H and Supertherm are registered trademarks of Duraloy Technologies, Inc.
(MO stands for Marty Ornitz, RE for Ray English)
Thermax and Thermalloy are registered trademarks of ElectroAlloys Corporation WASPALOY is a trademark of United Technologies Corporation
17-4PH and 18SR are registered trademarks of AK Steel Corporation
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COMPARISON – German & European Standards with American
2205 S31803 1.4462 X2CrNiMoN22-5-3 1.4462
2205 S32205 1.4462 X2CrNiMoN22-5-3 --
2507 S32750 1.4410 X2CrNiMoN25-7-4 1.4410
austenitic stainless
201 (stainless) S20100 1.4372 X12CrMnNiN 17-7-5 1.4372
303 S30300 1.4305 X8CrNiS18-9 1.4305
304L S30403 1.4307 X2CrNi18-9 1.4307
304 S30400 1.4301 X 5 CrNi 18 10 (X4CrNi18-10) 1.4301 304H S30409 1.4301 X 5 CrNi 18 10 (X4CrNi18-10) --
316 S31600 1.4401 X 5 CrNiMo 17 12 2 1.4401
316L S31603 1.4404 X2CrNiMo17-12-2 1.4404
316Ti S31635 1.4571 X6CrNiMo17-12-2 1.4571
317L S31703 1.4438 X2CrNiMo18-15-4 1.4438
321 S32100 1.4541, 1.4878 X6CrNiTi18-10, X12CrNiTi18-9 1.4541 321H S32109 1.4541, 1.4878 X6CrNiTi18-10, X12CrNiTi18-9 --
347 S34700 1.4550 X6CrNiNb18-10 --
310S S31008 1.4845 X8CrNi25-21 1.4845
310H S31009 1.4845 X8CrNi25-21 --
310 S31000 1.4845 X12CrNi25-21 --
314 S31400 1.4841 X15CrNiSi25-20 --
800 N08800 1.4876 X10NiCrAlTi32-20 --
800H N08810 1.4876 X10NiCrAlTi32-20 --
800HT®/ATTM N08811 (1.4959 similar) (X8NiCrAlTi32-21, similar) -- Incoloy® DS - -similar to - -1.4864 - -similar to - -X12NiCrSi36 16 --
weld filler metals—SG designates bare wire, EL is for covered electrodes
RA333 - - 2.4608 NiCr26MoW --
X (ERNiCrMo-2) 2.4613 SG-NiCr21Fe18Mo --
FM 602 CA - - 2.4649 SG-NiCr25FeAlY --
FM 617 (ERNiCrCoMo-1) 2.4627 SG-NiCr22Co12Mo --
FM 718 (ERNiFeCr-2) 2.4667 SG-NiCr19NbMoTi --
(AWS spec)
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COMPARISON—German & European Standards with American, continued
Grade UNS No. Werkstoff Nr. DIN Designation EN Number
age hardening alloys
17-4PH® S17400 1.4548 X5CrNiCuNb17-4-4 1.4542
A-286 S66286 1.4980 X5CrNiTi26-15 --
3127hMo N08031 1.4562 X1NiCrMoCu32-28-7 --
3033 R20033 1.4591 X1CrNiMoCuN33-32-1 --
20Cb-3® N08020 - - - - --
weld filler metals—SG designates bare wire, EL is for covered electrodes
70-30Cu-Ni ERCuNi 2.0837 SG-CuNi30Fe --
625 ERNiCrMo-3 2.4831 SG-NiCr21Mo9Nb --
112 ENiCrMo-3 2.4621 EL-NiCr20Mo9Nb --
82 ERNiCr-3 2.4806 SG-NiCr20Nb --
182 ENiCrFe-3 2.4620 EL-NiCr16FeMn --
UNS chemistries generally overlap the German standards shown but they are NOT identical. When the
customer requires DIN certification of stock material, it can be re-certified by the producing mill. Two exceptions are AL-6XN and 20Cb-3, as they have no direct German equivalents. RA330 does now have an EN spec, designation X10NiCrSi35-19, EN number 1.4886. DIN 50049 3.1.B is a general quality specification which can apply to any alloy. The producing mill can certify to this specification, or Rolled Alloys can provide a certificate ofconformance. Many of the EN (European Harmonized Standards) numbers and designations are
the same as DIN, others are not.
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