US3262777A - Ultra tough maraging steel - Google Patents

Ultra tough maraging steel Download PDF

Info

Publication number
US3262777A
US3262777A US382309A US38230964A US3262777A US 3262777 A US3262777 A US 3262777A US 382309 A US382309 A US 382309A US 38230964 A US38230964 A US 38230964A US 3262777 A US3262777 A US 3262777A
Authority
US
United States
Prior art keywords
steels
zirconium
boron
steel
toughness
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US382309A
Other languages
English (en)
Inventor
Sadowski Edward Peter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huntington Alloys Corp
Original Assignee
International Nickel Co Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE666818D priority Critical patent/BE666818A/xx
Application filed by International Nickel Co Inc filed Critical International Nickel Co Inc
Priority to US382309A priority patent/US3262777A/en
Priority to GB27749/65A priority patent/GB1039747A/en
Priority to CH948965A priority patent/CH449272A/fr
Priority to AT626265A priority patent/AT261650B/de
Priority to DEJ28558A priority patent/DE1233148B/de
Priority to LU49076A priority patent/LU49076A1/xx
Priority to NL6509043A priority patent/NL6509043A/xx
Application granted granted Critical
Publication of US3262777A publication Critical patent/US3262777A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten

Definitions

  • the present invention relates to ferrous-base alloys of high yield strength and, more particularly, to high strength steels which are exceedingly tough, the combination of toughness and high yield strength rendering the steels particularly suitable for use in the form of steel plate and welded structures fabricated therefrom.
  • the HTC steels are, as is well known, susceptible to weldability and embrittlement problems. With respect to the former, as the carbon content is increased, welding difficulties become more pronounced and, in this connection, it is the desideratum, commercially speaking, to keep the carbon content at a level of below about 0.3%, and preferably not much more than about 0.2%. But, as indicated above, it is the higher carbon contents which afford the high strength levels. In a sense, competing factors are involved.
  • a further distinct disadvantage to achieving good weldability characteristics with the HTC steels arises in connection with the fabrication of large structures such as huge pressure vessels and marine hulls. Such structures are generally formed from steel plates (e.g., /2 inch to several inches in thickness) welded to each other.
  • the aforementioned embrittlement problem is generated particularly in connection with the quenched and tempered steels. That is to say, when a steel is quenched and thereafter tempered, cooling through certain temperatures from tempering temperatures results 'in embrittlement. While a complete panacea is not now known which might obviate the embrittlement problem in all cases, it can be said that there has been a tendency, at least with regard to-many HTC steels, to use low tempering temperatures, e.g., 500 F. and lower, with a view of avoiding the embrittling temperature range. However, low tempering temperatures result in lower tensile elongation, reduction of area and the ability to absorb impact energy. These properties concern the more general charactristic of toughness.
  • Another object of the invention is to provide via a simple heat treatment a novel maraging steel characterized by an unusual combination of toughness and strength characteristics of an extremely high order of magnitude.
  • FIGURE 1 graphically depicts a general and illustrative relationship between the toughness and strength characteristics of the steels contemplated herein and the aluminum content thereof;
  • FIGURE 2 is another graphic representation which is generally illustrative of the effect of boron and zirconium and also silicon on impact strength of steels of the invention.
  • the alloy steels contemplated herein consist essentially (in percent by weight) of about 9.5% to 13.5% nickel, about 2.5% to about 8% chromium, about 1.9% to 4.2% molybdenum, up to 0.75% aluminum, e.g., about 0.05% to about 0.7% aluminum, up to about 0.3% titanium, up to 0.25% columbium, carbon in an amount up to about 0.03%, e.g., 0.001% to 0.03% carbon, up to 0.25 manganese, up to 0.5% silicon, up to not more than 0.0015% boron, up to not more than 0.01% and advantageously up to not more than 0.005%
  • the term balance or balance essentially when used to indicate the amount of iron in the alloy steels does not exclude the presence of other elements commonly present as incidental elements, e.g., deoxidizing and cleansing elements, and impurities ordinarily associated therewith in small amounts which do not adversely atfect basic
  • auxiliary elements such as beryllium, vanadium, tantalum and tungsten can be utilized in the steel of the instant invention. Such elements when used singly should not exceed the following amounts: 0.2% beryllium, 1% vanadium, 0.8% tantalum and 1% tungsten. When two or more auxiliary elements are utilized the total sum thereof should not exceed 2%.
  • Incidental elements such as cobalt and copper do not provide any particular attributes and, if desired, can be limited to those small amounts unavoidably introduced during commercial processing.
  • the alloy steels contain about 11.5% to 12.5% nickel, about 4.5% to about 5.5% chromium,
  • the steels upon aging exhibit yield strengths of up to about 200,000 p.s.i. or above, together with Charpy V-Notch impact values of at least 50 ft.-l-bs. at this strength level. Energy impact levels of about fL-lbS.
  • the nickel content of the steels should not fall below about 9.5%; otherwise there is an undesirable decrease in strength. Nickel contents greater than about 13.5% do not afford an appreciable advantage. Further, high nickel contents coupled with chromium contents on the high side of the chromium range could efliect a loss in strength. In this connection, the sum of the nickel and chromium contents should be at least about 14% and not greater than 19%. Chromium in an amount of less than 2.5% also results in lower strength levels. Amounts of molybdenum appreciably above the maximum specified herein adversely affect the toughness of the steels and there is a concomitant loss in strength. At least 1.9% and advantageously at least 2.75% molybdenum should be present for a good combination of toughness and yield strength.
  • the point of intersection of the curves in FIG. 1 shows a Charpy V-Notch energy level of about 68 ft.-lbs. together with a yield strength of about 188,000 p.s.i.
  • the silicon content not exceed about 0.12%, e.g., 0.1%. Silicon in amounts as low as 0.25% effects a marked reduction in toughness characteristics. While silicon contents of up to 0.35% or 0.5% can be used, it is significantly more advantageous to limit the silicon content to 0.1% Where optimum toughness is desired.
  • a further most satisfactory compositional range of alloying constituents contemplated herein is as follows: about 10.5% to 13% nickel, about 3.5% to 7.5% chromium, about 2.25% to 3.75% molybdenum, about 0.2% to 0.65% aluminum, up to 0.25% titanium, up to 0.2% columbium, e.g., 0.05% to 0.15% columbium, carbon up to 0.03%, up to not more than 0.0012% boron, up to 0.007% zirconium, up to 0.15% silicon, up to 0.15% manganese, and the balance essentially iron.
  • calcium can be used to effect a desulfurization, although the use of calcium is not necessary in vacuum processing.
  • Aluminum, titanium, silicon, manganese and, if any, boron and zirconium, are then added.
  • the cast ingots should be homogenized as by soaking at temperatures of about 2100 F. to 2350 F., e.g., 2300 F., followed by hot working and, if desired, cold working to desired shape.
  • the steels can suitably be worked at temperatures of 2000 F. to 1800 F., the finishing temperature being about 1700 F.
  • the steels are transformed to martensite by cooling to about room temperature and then applying a solution anneal treatment. While the final hot working temperature can be used in lieu of an anneal and the steels can then be aged after cooling from hot-working temperature, it is considerably more beneficial to effect a second martensitic transformation by cooling from hot working and then annealing followed by cooling. This procedure results in the attainment of tougher steels.
  • the solution annealing treatment comprises subjecting the steels to a temperature of about 1450 F. to 1900 F. for up to about 4 hours, e.g., /2 to 4 hours. In producing sheet material periods of less than 1 hour can be used.
  • a solution anneal temperature between about 1500 F. to 1600 F. for about 1 to 3 hours.
  • the steels pass through the M M range and, thus, again transform into .the martensitic condition.
  • the steels are aged at temperatures of about 800 F. to 1000 F. for about 1 to 24 hours or longer. It is advantageous that the aging temperature not exceed about 950 F. to avoid reversion to austenite. Long aging times at the higher aging temperatures are not recommended less overaging and/or reversion to austenite occur.
  • a recommended aging treatment consists of holding the steels at a temperature of about 875 F. to 925 F. for 2 to 4 hours.
  • the steels can be cooled to below room temperature prior to aging, e.g., down to minus F., as by, for example, refrigeration.
  • This technique can be adopted to assure complete transformation to martensite.
  • this treatment is generally unnecessary in accordance with the invention, i.e., substantially complete transformation occurs upon cooling from solution treatment.
  • Cold working prior to aging can also be used to effect the completion of transformation to martensite.
  • impurities e.g., sulfur (less than 0.005% in all alloys) and phosphorus (less than 000.35% in all alloys).
  • the alloy steels in Table I were melted in a vacuum induction furnace. Subsequent to solidification, cast ingots (4 x 4 inches) were soaked at 2300 F. to achieve good homogenization and then forged to 2 x 2 /2 inch specimens with two intermediate soaks at 2300 F. being employed. The specimens were than one-direction rolled in three passes to steel plate inch thick. The initial rolling temperature was 1800 F. with the rolling being finished at a temperature of about 1750 F. to 1650 F.
  • the steel plates were allowed to air coo-l to room temperature whereby the steels transformed to the martensitic condition.
  • Each of the steels was then solutiton treated (annealed) at about 1500 F. for about 1 hour, air cooled (to again achieve the martensitic condition) and then aged at about 900 F. for about 3 hours.
  • Table II illustrates the surprising and boron and/or zirconium contents are controlled in accordance with the concepts of the invention
  • the marked improvement can be more readily ascertained by reference to Table III wherein various alloys of Table I and corresponding data of Table II are set forth in a manner which affords a more convenient comparison.
  • the alloys given in Table III are presented on the basis that the compositions thereof are, practically speaking, essentially the same except for the boron and/ or zirconium contents (silicon and manganese are excluded from the tables so that composition plus yield strength and Charpy V-Notch impact values could be reported in one convenient table).
  • FIGURE 2 is also included herein to graphically depict a general effect of boron and/or zirconium in the alloys of Table III.
  • Table III illustrates the superior ability of the alloys nection with Table 1. Alloys Nos. 1 and 5 are included (Alloys 1 through 5) of the invention to absorb impact for the purpose of comparison.
  • alloy 2 As referred to herein, it is advantageous in accordance with preferred concepts of the invention that the alloy 2.
  • a maraging steel manifesting a unique ability to absorb extremely high levels of impact energy while simultaneously affording high levels of yield strength and consisting essentially of a composition falling within TABLE VI Alloy No. 0, Per- Ni, Per- Cr, Per- Mo, Per- Al, Per- Ti, Per- Si, Per- Mn, Per- B, Per- Zr, Per- Cb, Per- Y.S., C.V.N
  • Alloy 6 illustrates the beneficial efIect of columbium on C.V.N. energy levels in comparison with Alloy 5, an alloy of similar composition except that columbium was not added thereto. With columbium contents much above 0.25% (Alloy Q), Charpy V-Notch impact energy levels drop oil; however, Alloy 6 reflects that with amounts of columbium in accordance with the invention, impact energies of 100 ft.-lbs. can be obtained together with yield strength levels above about 180,000 p.s.i.
  • While the present invention is generally applicable to providing maraging steels in the forms of strip, bar, rod, sheet, etc., it is particularly applicable in providing maraging steels in plate form and in welded structures fabricated therefirom.
  • Other structures which can be formed from the steels contemplated herein include pressure vessels, ships hulls, rotors for electrical generators, etc.
  • the high level of toughness of steels described render the steels eminently suitable for cryogenic application down to temperatures of the order of minus 320 F. This feature is decidedly beneficial in view of the greatly expanded utilization of vessels and the like for storage of liquids and gasees at low temperature.
  • a maraging steel manifesting a unique ability to absorb extremely high levels of impact energy of about (a) 75 foot-pounds and above While simultaneously affording a high level of yield strength of at least about 175,000 p.s.i., and (b) about 50 foot-pounds and above while affording a yield strength of about 200,000 p.s.i., and consisting essentially of a composition falling within the following ranges: about 11.5% to 12.5% nickel, about 4.5% to 5.5% chromium, about 2.75% to 3.25%
  • a novel maraging steel consisting essentially of about 9.5% to 13.5% nickel, about 2.5% to 8% chromium, about 1.9% to 4.2% molybdenum, up to about 0.75% aluminum, up to about 0.3% titanium, up to about 0.25% columbium, carbon in an amount up to 0.03%, up to 0.25% manganese, up to 0.5% silicon, up to not more than 0.0015 boron and up to not more than 0.01% zirconium to thereby greatly minimize their influence in adversely affecting the toughness characteristics of said steel, up to about 0.2% iberyllium, up to about 1% vanadium, up to about 0.8% tantalum, up to about 1% tungsten, with the total amount of beryllium, vanadium, tantalum and tungsten not exceeding 2%, and the balance essentially iron.
  • a novel maraging steel consisting essentially of about 9.5% to 13.5% nickel, about 2.5% to 8% chromium, about 1.9% to 4.2% molybdenum, up to about 0.75% aluminum, up to about 0.3% titanium, up to about 0.25% columbium, carbon in an amount up to 0.03%, up to 0.25% manganese, up to 0.5% silicon, at least one element selected from the group consisting of boron and zirconium, the amount of boron not exceeding 0.0015% and the amount of zirconium not exceeding 0.01% to thereby greatly minimize their influence in adversely afiecting the toughness characteristics of said steel, and the balance essentially iron.
US382309A 1964-07-13 1964-07-13 Ultra tough maraging steel Expired - Lifetime US3262777A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
BE666818D BE666818A (de) 1964-07-13
US382309A US3262777A (en) 1964-07-13 1964-07-13 Ultra tough maraging steel
GB27749/65A GB1039747A (en) 1964-07-13 1965-06-30 Alloy steel
CH948965A CH449272A (fr) 1964-07-13 1965-07-07 Acier martensitique
AT626265A AT261650B (de) 1964-07-13 1965-07-09 Martensitischer Stahl und Verfahren zu seiner Wärmebehandlung
DEJ28558A DE1233148B (de) 1964-07-13 1965-07-10 Verwendung einer martensitaushaertbaren Stahllegierung fuer druck- und schlagfeste Gegenstaende
LU49076A LU49076A1 (de) 1964-07-13 1965-07-13
NL6509043A NL6509043A (de) 1964-07-13 1965-07-13

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US382309A US3262777A (en) 1964-07-13 1964-07-13 Ultra tough maraging steel

Publications (1)

Publication Number Publication Date
US3262777A true US3262777A (en) 1966-07-26

Family

ID=23508401

Family Applications (1)

Application Number Title Priority Date Filing Date
US382309A Expired - Lifetime US3262777A (en) 1964-07-13 1964-07-13 Ultra tough maraging steel

Country Status (8)

Country Link
US (1) US3262777A (de)
AT (1) AT261650B (de)
BE (1) BE666818A (de)
CH (1) CH449272A (de)
DE (1) DE1233148B (de)
GB (1) GB1039747A (de)
LU (1) LU49076A1 (de)
NL (1) NL6509043A (de)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3342590A (en) * 1964-09-23 1967-09-19 Int Nickel Co Precipitation hardenable stainless steel
US3347663A (en) * 1964-09-23 1967-10-17 Int Nickel Co Precipitation hardenable stainless steel
US3392065A (en) * 1965-10-15 1968-07-09 Int Nickel Co Age hardenable nickel-molybdenum ferrous alloys
US3479157A (en) * 1965-06-25 1969-11-18 Int Nickel Co Welded articles and alloys containing hafnium and nickel
US3532491A (en) * 1966-08-25 1970-10-06 Int Nickel Co Maraging steel suitable for heavy section applications
US3899368A (en) * 1973-12-13 1975-08-12 Republic Steel Corp Low alloy, high strength, age hardenable steel
US4146409A (en) * 1977-06-06 1979-03-27 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Process for making a high toughness-high strength iron alloy
US4214902A (en) * 1979-01-25 1980-07-29 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration High toughness-high strength iron alloy
US4579590A (en) * 1983-03-16 1986-04-01 Mitsubishi Jukogyo Kabushiki Kaisha High strength cobalt-free maraging steel
US20160340752A1 (en) * 2015-05-22 2016-11-24 Daido Steel Co., Ltd. Maraging steel
US20160340753A1 (en) * 2015-05-22 2016-11-24 Daido Steel Co., Ltd. Maraging steel
US11286534B2 (en) 2018-07-18 2022-03-29 The Boeing Company Steel alloy and method for heat treating steel alloy components

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2999039A (en) * 1959-09-14 1961-09-05 Allegheny Ludlum Steel Martensitic steel
US3093519A (en) * 1961-01-03 1963-06-11 Int Nickel Co Age-hardenable, martensitic iron-base alloys
US3123506A (en) * 1964-03-03 Alloy steel and method
US3151978A (en) * 1960-12-30 1964-10-06 Armco Steel Corp Heat hardenable chromium-nickel-aluminum steel
US3164497A (en) * 1963-02-08 1965-01-05 North American Aviation Inc Progressive slope aging process

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT146720B (de) * 1931-06-23 1936-08-10 Krupp Ag Herstellung von Gegenständen, die besondere Festigkeitseigenschaften, insbesondere eine hohe Schwingungsfestigkeit besitzen müssen und/oder hohe Beständigkeit gegen Brüchigwerden durch interkristalline Korrosion aufweisen sollen.

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3123506A (en) * 1964-03-03 Alloy steel and method
US2999039A (en) * 1959-09-14 1961-09-05 Allegheny Ludlum Steel Martensitic steel
US3151978A (en) * 1960-12-30 1964-10-06 Armco Steel Corp Heat hardenable chromium-nickel-aluminum steel
US3093519A (en) * 1961-01-03 1963-06-11 Int Nickel Co Age-hardenable, martensitic iron-base alloys
US3164497A (en) * 1963-02-08 1965-01-05 North American Aviation Inc Progressive slope aging process

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3342590A (en) * 1964-09-23 1967-09-19 Int Nickel Co Precipitation hardenable stainless steel
US3347663A (en) * 1964-09-23 1967-10-17 Int Nickel Co Precipitation hardenable stainless steel
US3479157A (en) * 1965-06-25 1969-11-18 Int Nickel Co Welded articles and alloys containing hafnium and nickel
US3392065A (en) * 1965-10-15 1968-07-09 Int Nickel Co Age hardenable nickel-molybdenum ferrous alloys
US3532491A (en) * 1966-08-25 1970-10-06 Int Nickel Co Maraging steel suitable for heavy section applications
US3899368A (en) * 1973-12-13 1975-08-12 Republic Steel Corp Low alloy, high strength, age hardenable steel
US4146409A (en) * 1977-06-06 1979-03-27 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Process for making a high toughness-high strength iron alloy
US4214902A (en) * 1979-01-25 1980-07-29 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration High toughness-high strength iron alloy
US4579590A (en) * 1983-03-16 1986-04-01 Mitsubishi Jukogyo Kabushiki Kaisha High strength cobalt-free maraging steel
US20160340752A1 (en) * 2015-05-22 2016-11-24 Daido Steel Co., Ltd. Maraging steel
US20160340753A1 (en) * 2015-05-22 2016-11-24 Daido Steel Co., Ltd. Maraging steel
US10337079B2 (en) * 2015-05-22 2019-07-02 Daido Steel Co., Ltd. Maraging steel
US10378072B2 (en) * 2015-05-22 2019-08-13 Daido Steel Co., Ltd. Maraging steel
US11286534B2 (en) 2018-07-18 2022-03-29 The Boeing Company Steel alloy and method for heat treating steel alloy components

Also Published As

Publication number Publication date
GB1039747A (en) 1966-08-24
BE666818A (de)
DE1233148B (de) 1967-01-26
NL6509043A (de) 1966-01-14
CH449272A (fr) 1967-12-31
AT261650B (de) 1968-05-10
LU49076A1 (de) 1965-09-13

Similar Documents

Publication Publication Date Title
US3567434A (en) Stainless steels
US4295769A (en) Copper and nitrogen containing austenitic stainless steel and fastener
US3556776A (en) Stainless steel
US3366471A (en) High strength alloy steel compositions and process of producing high strength steel including hot-cold working
JPS6411105B2 (de)
KR20080034939A (ko) 내식성, 냉간 성형성 및 기계 가공성을 갖는 고강도마르텐사이트계 스테인리스강
US3262777A (en) Ultra tough maraging steel
USRE28523E (en) High strength alloy steel compositions and process of producing high strength steel including hot-cold working
US4610734A (en) Process for manufacturing corrosion resistant chromium steel
US3532491A (en) Maraging steel suitable for heavy section applications
GB2133037A (en) Stainless duplex ferritic- austenitic steel, articles made therefrom and method of enhancing intergranular corrosion resistance of a weld of the stainless duplex ferritic austenitic steel
JPH0114305B2 (de)
US3359094A (en) Ferrous alloys of exceptionally high strength
US3132937A (en) Cast steel
US3453102A (en) High strength,ductile maraging steel
EP0327042A1 (de) Martensitaushärtbarer Stahl
US3355280A (en) High strength, martensitic stainless steel
US3342590A (en) Precipitation hardenable stainless steel
US3347663A (en) Precipitation hardenable stainless steel
US3318690A (en) Age hardening manganese-containing maraging steel
US4047941A (en) Duplex ferrit IC-martensitic stainless steel
US3132025A (en) Alloy steel
US4832765A (en) Duplex alloy
US3294527A (en) Age hardening silicon-containing maraging steel
JPS6119767A (ja) 低温用オーステナイト系ステンレス鋼