US3813240A - Corrosion-resisting steel - Google Patents

Corrosion-resisting steel Download PDF

Info

Publication number
US3813240A
US3813240A US00264985A US26498572A US3813240A US 3813240 A US3813240 A US 3813240A US 00264985 A US00264985 A US 00264985A US 26498572 A US26498572 A US 26498572A US 3813240 A US3813240 A US 3813240A
Authority
US
United States
Prior art keywords
corrosion
steel
chromium
titanium
corrosion resistance
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
US00264985A
Other languages
English (en)
Inventor
Y Abe
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.)
Mitsubishi Steel Mfg Co Ltd
Mitsubishi Steel KK
Original Assignee
Mitsubishi Steel Mfg Co Ltd
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
Application filed by Mitsubishi Steel Mfg Co Ltd filed Critical Mitsubishi Steel Mfg Co Ltd
Application granted granted Critical
Publication of US3813240A publication Critical patent/US3813240A/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
    • C22C33/00—Making ferrous alloys
    • C22C33/02—Making ferrous alloys by powder metallurgy
    • C22C33/0257—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
    • C22C33/0278—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements with at least one alloying element having a minimum content above 5%
    • C22C33/0292—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements with at least one alloying element having a minimum content above 5% with more than 5% preformed carbides, nitrides or borides

Definitions

  • FIG. 2 ' 400 560 660 s' oo 9'00 I600 II'oo 3 7 -HEAT TREATMENT TEMPERATURE (C)- May 28 1974 Filed June 21, 1972 FIG. 2
  • FIG. 2A is a diagrammatic representation of FIG. 1A
  • FIG. 1 A first figure.
  • FIGS. 1 and 1(a) show the result of tests, in which the US. (1 75- 6 D 2 Claims efi'ect of molybdenum quantity contained in the steel ac- 10 cording to the present invention was tested in 2% and ABSTRACT OF THE DISCLOSURE 35% hydrochloric acid solutions;
  • FIGS. 2 and 2(a) show the results of tests, in which the P T' steel superb ,Teslstance 1 effect of aluminum quantity contained in the steel accordplthng 1S manufactmled of a mlcmstfucmra ing to the present invention was tested in 33% and 65% stainless steel composed mainly of chromium or 5 nitric acid Soluions; chfomlum aflded f at least of mcke ⁇ and FIG.
  • FIG. 3 shows the test result of six samples in Table 2 manganese still containing 10 to 30 percent by weight of comparing their corrosion resistances under several chromium and further having 2 to 10 percent by weigh; conditions of heat treatment; and h or lhore p z selected from the 0
  • FIG. 4 shows a quantitative relation of copper and tlthmum, Zlrcomum, P tantalflm and vanadmm titanium causing an improvement on corrosion resistance uniformly and finely dispersed therein.
  • the steel according to the present invention is produced
  • the present invention relates to corrosion-resisting by a Promss whlch the mcflten steel much steels, and more particularly to steels with superb excess carbon compared W1 th Oxygen, hlh'ogell and resistance to pitting corrosion and excellent corrosion cfmtents are added some elementF to form resistance against any kind of acid solution.
  • corrosion resistance is an indespensahle with carbon
  • the thus-obtained solid carbides are unicharacteristic for steels to be used in corrosive a a dlspersed Preclpltated 95 wlth the sohd circumstances and it is well known that many kinds of nitrides and the dispersed carbonitrides must be stable stainless steel have so far been developed for use under even under hot and 9F conditions thereafter such circumstances.
  • Table 1 shows that it is necessary to add or more chromium into the matrix to completely prevent corrosion of the steel regardless the micro-structure of the matrix.
  • any kind of carbonitride increases its resistance to pitting corrosion, if 2.0% or more of sole carbonitride of titanium or zirconium, or complex carbonitride of titanium and niobium, titanium and vanadium, or zirconium and tantalum are dispersed into the matrix containing 10% or more chromium. Therefore, in the steel according to the present invention, it is inevitable to precipitate dispersely 2% or more carbonitride abovementioned into the steel.
  • any kind of existing stainless steels can be applied, whether the structure of matrix is ferrite containing chromium as 4,
  • the corrosion resistance of the steel of the present invention to sulfuric acid can be remarkably increased by containing three elements, nickel, copper and titanium together in the matrix.
  • FIG. 3 represents a comparison of corrosion resistances to 5% sulfuric acid solution of six samples having different quantities of nickel, copper and titanium in the matrix as shown in Table 2. It is found out that adding only two elements combined, copper and nickel, copper and titanium or nickel and titanium does not show marked effect to corrosion resistance, but the ferritic steel containing three elements, nickel, copper and titanium, together has excellent corrosion resistance under the condition of 500-800 C. heat treatment and the austenitic steel containing three elements above mentioned, has also strong corrosion resistance under any condition of heat treatment.
  • TAB LE 2 Dispersed carbonitrlde Components in matrlx, percent a main component of alloy, or ferrite-austenite or austenite containing one or two elements of chromium, nickel and manganese.
  • maximum quantities of dispersed carbonitride and chromium are limited from the production engineering standpoint, and it is desired that quantity of carbonitride is limited to 10% or less owing to fluidity and quantity of chromium is limited to or less due to plasticity.
  • the corrosion resistance of the steel according to the present invention to acid solution containing chloridion can be remarkably improved by containing molybdenum in the matrix.
  • FIGS. 1 and 1(a) shows the variation of corrosion rate of the steel according to the present invention in hydrochloric acid solutions of difiFerent concentrations against the quantitative change of molybdenum content in the matrix.
  • the effect of molybdenum appears conspicuously about 0.7% and saturates about 4% Therefore quantity of molybdenum content may be limited to 05-50%.
  • the etfect of added molybdenum is not influenced by quantity of chromium or carbonitride as far as the steel of the present invention is cornerned.
  • FIGS. 2 and 2(a) represent the variation of corrsion rate of the steel against quantities of aluminum in its matrix containing 18% and 25% chromium respectively, and having 3.55.0% various carbonitrides dispersed.
  • quantity of aluminum may be limited to 0.2l.0% in maintaining its efiect sutficiently.
  • quantity of nickel shall be preferably more than 1.5 times that of copper to prevent hot brittleness due to copper.
  • FIG. 4 shows the domain of corrosion resistance rate of the steel against various quantities of copper and titanium, keeping quantity of nickel content 1.5 times that of copper. Minimum quantities to improve the corrosion resistance are 0.4% copper and 0.2% titanium.
  • ferrite-austenitic steel and austenitic steel containing 10- 30% chromium and at least 3% nickel shall have 2-10% said carbonitride dispersed into the matrix containing 0.4- 20% copper and 0.21.5% titanium, and other stainless steel shall have the same quantity of carbonitride dispersed into the matrix containing 0.63.0% nickel additionally.
  • one or two elements of 0.5-5.0% molybdenum and 0.21.0% aluminum shall be added.
  • EXAMPLE 1 SUS24B containing 16-18% chromium as a main component and the steel according to the present invention in which 3.2% by weight of complex carbonitride of titanium and niobium was dispersed, were immerged in acid solution containing 5.0% chloridion. Pitting corrosion appeared on SUS24B in three days, but no corrosion was found on the invented steel after ten days.
  • Test pieces of 25 x x 50 mm. were cut oif from the two steels and they were immerged in boiling solution of sulfuric acid containing 10% copper sulphide for one hour.
  • EXAMPLE 2 SUS42B, which contains 24-26% chromium, 19-22% nickel as main alloy components, is the highest grade stainless steel having excellent corrosion resistance.
  • the steel according to the present invention which has carbonitride containing 4.0% titanium carbide as a main component, dispersed in the matrix having only 2% molybdenum besides the same quantity of chromium as SUS42B, was tested for corrosion resistance comparing with SUS42B in acid solution containing chloridion.
  • the invented steel proved to have extraordinarily excellent corrosion resistance judging from both corrosion appearance and corrosion rate, and the difference was obvious in sodium chloride solution.
  • Corrosion rate gJmfl/day (corrosion appearance) Corrosive solution EXAMPLE 3 The steel according to the present invention which has carbonitride containing 3.7% titanium carbide as a main component, dispersed in the matrix containing 18% chromium, 1.2% nickel, 0.75% copper, 0.25% titanium, 2.0% molybdenum, was heat-treated at 650 C. and tested for corrosion resistance in various acid solutions comparing with 18% chromium, 8% nickel stainless steel (SUS27B) most commonly used.
  • the test result shown in Table 4 reveals that the steel of the present invention is slightly inferior to SUS27B in corrosion resistance to nitric acid, but it is superior in corrosion resistance to sulfuric acid, and moreover it has specific high corrosion resistance in acid solution containing hydrochloric acid and chloridion.
  • a corrosion-resistant steel having a microstructure consisting essentially of 2-10% by weight of a carbonitride of one or more elements selected from the group consisting of titanium, zirconium, niobium, tantalum and vanadium uniformly and finely dispersed in a stainless steel consisting essentially of 10-30% of chromium, an eflective amount up to 0.2% of phosphorus, an efiective amount up to 0.2% boron and the balance being iron.
  • a corrosion resisting steel having a microstructure consisting essentially of 2-l0% by weight of a carbonitride of one or more elements of titanium, zirconium, niobium, tantalum and vanadium uniformly and finely dispersed into the stainless steel, 10-30% by weight of chromium, one or more elements of less than 0.2% boron or phosphorous, 0.5-5.0% by weight of molybdenum, 0.2l.0% by weight of aluminum','0.4-2.0% by weight of copper, O.6-3.0% by weight of nickel, 0.21.5% by weight of titanium, and the balance being iron.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)
US00264985A 1972-03-03 1972-06-21 Corrosion-resisting steel Expired - Lifetime US3813240A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP47021554A JPS4889820A (US08188275-20120529-C00054.png) 1972-03-03 1972-03-03

Publications (1)

Publication Number Publication Date
US3813240A true US3813240A (en) 1974-05-28

Family

ID=12058209

Family Applications (1)

Application Number Title Priority Date Filing Date
US00264985A Expired - Lifetime US3813240A (en) 1972-03-03 1972-06-21 Corrosion-resisting steel

Country Status (3)

Country Link
US (1) US3813240A (US08188275-20120529-C00054.png)
JP (1) JPS4889820A (US08188275-20120529-C00054.png)
DE (1) DE2231032A1 (US08188275-20120529-C00054.png)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3963532A (en) * 1974-05-30 1976-06-15 E. I. Du Pont De Nemours And Company Fe, Cr ferritic alloys containing Al and Nb
US4140526A (en) * 1976-11-12 1979-02-20 Sumitomo Metal Industries, Ltd. Ferritic stainless steel having improved weldability and oxidation resistance
US4391634A (en) * 1982-03-01 1983-07-05 Huntington Alloys, Inc. Weldable oxide dispersion strengthened alloys
US4418859A (en) * 1981-05-29 1983-12-06 General Electric Company Method of making apparatus for the exchange of heat using zirconium stabilized ferritic stainless steels
US8623197B1 (en) * 2010-12-20 2014-01-07 Western Digital (Fremont), Llc Testing workpiece overcoat

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3963532A (en) * 1974-05-30 1976-06-15 E. I. Du Pont De Nemours And Company Fe, Cr ferritic alloys containing Al and Nb
US4140526A (en) * 1976-11-12 1979-02-20 Sumitomo Metal Industries, Ltd. Ferritic stainless steel having improved weldability and oxidation resistance
US4418859A (en) * 1981-05-29 1983-12-06 General Electric Company Method of making apparatus for the exchange of heat using zirconium stabilized ferritic stainless steels
US4391634A (en) * 1982-03-01 1983-07-05 Huntington Alloys, Inc. Weldable oxide dispersion strengthened alloys
US8623197B1 (en) * 2010-12-20 2014-01-07 Western Digital (Fremont), Llc Testing workpiece overcoat

Also Published As

Publication number Publication date
JPS4889820A (US08188275-20120529-C00054.png) 1973-11-24
DE2231032A1 (de) 1973-09-20

Similar Documents

Publication Publication Date Title
US3615365A (en) Austenitic stainless steel
US3813240A (en) Corrosion-resisting steel
US2858206A (en) Nickel-free, low-alloy, high-strength steel
US3552950A (en) High temperature corrosion resistant fe-g-ni-mn alloy
US3563729A (en) Free-machining corrosion-resistant stainless steel
US3989474A (en) Austenitic stainless steel
US2984563A (en) Stainless steel and method
US2865740A (en) Precipitation-hardening nonmagneticferrous alloys
US3940266A (en) Austenitic stainless steel
US3075839A (en) Nickel-free austenitic corrosion resistant steels
US3113862A (en) High speed steel
US2996376A (en) Low alloy steel having high hardness at elevated temperatures
US3249426A (en) Low-nickel ductile steel
US3677744A (en) Age hardening stainless steel
US1979594A (en) Manganese - molybdenum - vanadium steel and articles made therefrom
US3070438A (en) Heat treated alloy steels
US2280796A (en) Phosphorus titanium steel
US3698889A (en) Non-magnetisable steel
US2172023A (en) Heat-resistant alloy
US1962702A (en) Corrosion resistant ferrous alloy comprising chromium, nickel, manganese and copper
US1835151A (en) Steel alloy
US2236975A (en) Copper-zinc alloys
US1919211A (en) Alloy steel
US3666448A (en) Copper/iron/aluminium alloys
US3932174A (en) Chromium, molybdenum ferritic stainless steels