US3834950A - Ferrous alloys - Google Patents

Ferrous alloys Download PDF

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Publication number
US3834950A
US3834950A US00266703A US26670372A US3834950A US 3834950 A US3834950 A US 3834950A US 00266703 A US00266703 A US 00266703A US 26670372 A US26670372 A US 26670372A US 3834950 A US3834950 A US 3834950A
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Prior art keywords
alloys
chromium
carbides
alloy
content
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US00266703A
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English (en)
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M Feltz
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    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
    • B02C17/18—Details
    • B02C17/20—Disintegrating members
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C37/00—Cast-iron alloys
    • C22C37/06—Cast-iron alloys containing chromium
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23H—GRATES; CLEANING OR RAKING GRATES
    • F23H17/00—Details of grates
    • F23H17/12—Fire-bars

Definitions

  • High chromium-carbon ferrous alloys have long been known to be particularly useful for the manufacture of elements and equipment parts which are to be subjected to abrasion, corrosion, hot oxidation and repeated impacts.
  • high chromium-carbon alloys are particularly well suited for use as grinding balls, cylpebs, lining plates, screens, classification parts, grate bars for furnaces, parts of turbines, etc.
  • These higher chromium alloyed cast irons have a useful limit of about 35% of chromium carbides of the (Fe, Cr) C type.
  • the higher chromium content alloyed cast irons have carbides which are harder than the cementite (Fe C) of the alloys characterized by less than 10% chromium, the maximum percentage of carbides which can be employed without rendering the alloys too brittle is reduced.
  • the present invention overcomes the above briefly discussed and other disadvantages and deficiencies of the prior art by providing novel and improved ferrous alloys with a high content of chromium and carbon and characterized by a high content of hard primary eutectic and hypereutectic chromium carbides in a martensitic matrix.
  • the alloys in accordance with the invention accordingly, have significantly improved wear resistance properties when compared to the prior art while simultaneously having mechanical properties and impact resistance sufiiciently high to resist the repeated impacts encountered by grinding media in, for example, ball mills.
  • the ferrous alloys of the present invention have a composition by weight corresponding to the following analysls:
  • the balance being substantially iron with the usual impurity contents for commercial cast iron, mainly sulphur and phosphorous.
  • impurity contents for commercial cast iron, mainly sulphur and phosphorous.
  • the phrase usual impurity contents is intended to encompass sulphur within the range of 0.01 to 0.15% and phosphorous within the range of 0.01 to 0.15%.
  • the carbon and chromium contents of the alloys in accordance with the present invention are bound by the following relationship:
  • the ferrous alloys of the invention are also characterized by a metallographic structure constituted by a martensitic solid solution without ferrite and containing eutectic and hypereutectic carbides, but being free of secondary proeutectoid carbides; such alloys having a hardness equal or superior to 60 on the Rockwell C scale.
  • Alloys in accordance with the present invention having a composition within the bounds set forth above, contain chromium carbides which are mainly of the (Fe, Cr) C type. Such chromium carbides are of relatively small dimensions and thus form a close bond with the matrix.
  • chromium alloyed cast irons having contents of chromium carbide ranging from 35 to and showing a hypereutectic structure mating perfectly into the matrix, may be cast and the resulting products are particularly well suited for the manufacture of grinding media.
  • alloys in accordance with the invention have a mainly ferritic matrix and a hardness which ranges from 30 to 45 on the Rockwell C scale depending on the primary carbide content. Such cast alloys may be easily machined. Further, such alloys, despite their ferritic struc ture, can be submitted to a hardening heat-treatment to convert the ferrite into hard martensite by austenitization.
  • the duration of the austenitization is preferably between 1 and hours depending upon the dimensions of the piece being treated and cooling can be performed in either blown or still air.
  • the alloys After hardening the alloys have a hardness equal to or superior to r 60 on the Rockwell C scale and, in some cases, hardness in the range of R 63 to 66 has been measured.
  • FIG. 1 depicts the microstructure of an alloy in accordance with the invention after hardening, FIG. 1 being at a magnification of 200;
  • FIG. 2 depicts the alloy of FIG. 1 with a magnification of 500.
  • the depicted microstructure shows the hypereutectic and eutectic carbides and the matrix which is a martensitic solid solution containing an amount of residual austenite but no ferrite.
  • the alloys in accordance with the invention do not contain secondary pro-eutectoid carbides and thus have improved corrosion resistance, for example during grinding by wet processes, when compared to the prior art. Martensitic cast irons which were free of secondary carbides have not previously been available.
  • one of the particularly unique features of the present invention is the provision of high chromium and carbon alloys of martensitic metallographic structure containing eutectic and hypereutectic carbides and being free of secondary carbides.
  • the alloys in accordance with the present invention after hardening in blown or still air, may be subjected to a stress-relief heat treatment in the range of 100 to 300 C. to eliminate residual stresses. Subsequent to the hardening step, in order to decrease the residual austenite content, it may in some cases be advisable to subject the alloys to a tempering heat-treatment in the range of 450 to 550 C. or to a cold treatment which may reach 200 C. below zero. In the case of a cold treatment, the residual tensions may also be removed by a stress-relief heat-treatment in the 100 to 300 C. range.
  • composition of the invention within the bounds set forth above, is characterized by the following analysis by weight:
  • the wear resistance of the alloys can be improved by adding, to an alloy selected Within the above stated range of the four principal components, molybdenum in an amount of 0 to 2.5%, niobium in an amount between 0 to 2.5 or both elements simultaneously in a total amount between 0 to 5% wherein neither one of the added alloy elements individually exceeds 2.5% by weight.
  • molybdenum in an amount of 0 to 2.5%
  • niobium in an amount between 0 to 2.5 or both elements simultaneously in a total amount between 0 to 5% wherein neither one of the added alloy elements individually exceeds 2.5% by weight.
  • the percentages being by weight and the balance of both alloys being mainly iron with small amounts of impurities such as phosphorous and sulphur.
  • the alloys according to the invention have clearly superior wear resistance when compared to the prior art.
  • the present alloys also have excellent wear resistance when exposed to corrosion phenomena such as, for example, is experienced in the grinding of ores by wet process.
  • the present alloys have excellent wear resistance when submitted to hot oxidation phenomena such as, again by way of example, isexperienced during the grinding of slags.
  • Heabtreated cast ferrous alloys having a high resistance to wear and consisting essentially in weight percent of:
  • the balance being iron but containing impurities, such as sulphur and phosphorus up to 0.15%; wherein the total weight percent of carbon and chromium satisfy the relationship Percent Cr-8Xpercent 0:11 to 16;
  • the ferrous alloy according to claim 1 further containing an eifective amount of molybdenum up to 2.5%.
  • the ferrous alloy according to claim 1 further containing an effective amount of niobium up to 2.5%.
  • ferrous alloy according to claim 1 further containing an effective amount of both molybdenum and niobium up to 5%, the content of neither molybdenum nor niobium exceeding 2.5%.
  • the ferrous alloy according to claim 2 further containing an effective amount of molybdenum up to 2.5%.
  • the ferrous alloy according to claim 2 further containing an effective amount of niobium up to 2.5%.
  • the ferrous alloy according to claim 2 further containin g an effective amount of molybdenum and niobium up to 5%, the content of neither molybdenum nor niobium exceeding 2.5%.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Combustion & Propulsion (AREA)
  • General Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Crushing And Grinding (AREA)
  • Heat Treatment Of Articles (AREA)
  • Powder Metallurgy (AREA)
  • Crushing And Pulverization Processes (AREA)
US00266703A 1971-06-29 1972-06-27 Ferrous alloys Expired - Lifetime US3834950A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
LU63431 1971-06-29

Publications (1)

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US3834950A true US3834950A (en) 1974-09-10

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US00266703A Expired - Lifetime US3834950A (en) 1971-06-29 1972-06-27 Ferrous alloys

Country Status (15)

Country Link
US (1) US3834950A (fr)
JP (1) JPS527406B1 (fr)
AU (1) AU470081B2 (fr)
BE (1) BE785431A (fr)
BR (1) BR7204244D0 (fr)
CA (1) CA990105A (fr)
DE (1) DE2230864C3 (fr)
FI (1) FI60241C (fr)
GB (1) GB1390011A (fr)
IT (1) IT959133B (fr)
LU (1) LU63431A1 (fr)
NO (1) NO131301C (fr)
OA (1) OA04125A (fr)
SE (1) SE408806C (fr)
ZA (1) ZA723826B (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5035150A (en) * 1986-08-14 1991-07-30 Kontron Instruments Holdings, N.V. Pipetting method
US5230755A (en) * 1990-01-22 1993-07-27 Sulzer Brothers Limited Protective layer for a metal substrate and a method of producing same
US6165288A (en) * 1994-05-17 2000-12-26 Ksb Aktienegsellschaft Highly corrosion and wear resistant chilled casting
US20100147247A1 (en) * 2008-12-16 2010-06-17 L. E. Jones Company Superaustenitic stainless steel and method of making and use thereof
US9284631B2 (en) * 2014-05-16 2016-03-15 Roman Radon Hypereutectic white iron alloys comprising chromium and nitrogen and articles made therefrom
US9580777B1 (en) 2016-02-08 2017-02-28 Roman Radon Hypereutectic white iron alloys comprising chromium, boron and nitrogen and articles made therefrom
RU2663950C1 (ru) * 2018-01-09 2018-08-13 Юлия Алексеевна Щепочкина Сплав
CN109563573A (zh) * 2016-06-24 2019-04-02 伟尔矿物澳大利亚私人有限公司 耐侵蚀和腐蚀性白口铸铁
CN113025874A (zh) * 2021-03-29 2021-06-25 北京工业大学 一种过共晶高铬铸铁及其孕育变质处理方法
CN114929906A (zh) * 2020-01-16 2022-08-19 曼格特奥克斯国际有限公司 用于半自体研磨机的锻造研磨球

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE785255A (fr) * 1972-06-22 1972-10-16 Soudure Autogene Elect Alliages de rechargement a l'arc electrique ainsi que les electrodes enrobees, fils fourres ou soudures en poudre a mettre en oeuvre pour les obtenir.
WO1979000274A1 (fr) * 1977-11-11 1979-05-17 Fischer Ag Georg Procede de fabrication de pieces metalliques en alliage de fonte fe/cr destinees a etre exposees a l'usure
ZA844074B (en) * 1983-05-30 1986-04-30 Vickers Australia Ltd Abrasion resistant materials
US4547221A (en) * 1984-10-26 1985-10-15 Norman Telfer E Abrasion-resistant refrigeration-hardenable ferrous alloy
AU636902B2 (en) * 1989-08-04 1993-05-13 Warman International Limited A ferrochromium alloy
KR940003890B1 (ko) * 1989-08-04 1994-05-04 와맨 인터내셔날 리미티드 내식성 페로크롬(ferrochromium) 합금과 그 제조방법
CN113897475A (zh) * 2021-07-20 2022-01-07 宁国市华丰耐磨材料有限公司 一种高铬磨球分级淬火热处理工艺

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5035150A (en) * 1986-08-14 1991-07-30 Kontron Instruments Holdings, N.V. Pipetting method
US5230755A (en) * 1990-01-22 1993-07-27 Sulzer Brothers Limited Protective layer for a metal substrate and a method of producing same
US6165288A (en) * 1994-05-17 2000-12-26 Ksb Aktienegsellschaft Highly corrosion and wear resistant chilled casting
US20100147247A1 (en) * 2008-12-16 2010-06-17 L. E. Jones Company Superaustenitic stainless steel and method of making and use thereof
US8430075B2 (en) 2008-12-16 2013-04-30 L.E. Jones Company Superaustenitic stainless steel and method of making and use thereof
US9284631B2 (en) * 2014-05-16 2016-03-15 Roman Radon Hypereutectic white iron alloys comprising chromium and nitrogen and articles made therefrom
US9580777B1 (en) 2016-02-08 2017-02-28 Roman Radon Hypereutectic white iron alloys comprising chromium, boron and nitrogen and articles made therefrom
CN109563573A (zh) * 2016-06-24 2019-04-02 伟尔矿物澳大利亚私人有限公司 耐侵蚀和腐蚀性白口铸铁
US11873545B2 (en) 2016-06-24 2024-01-16 Weir Minerals Australia Ltd. Erosion and corrosion resistant white cast irons
RU2663950C1 (ru) * 2018-01-09 2018-08-13 Юлия Алексеевна Щепочкина Сплав
CN114929906A (zh) * 2020-01-16 2022-08-19 曼格特奥克斯国际有限公司 用于半自体研磨机的锻造研磨球
CN113025874A (zh) * 2021-03-29 2021-06-25 北京工业大学 一种过共晶高铬铸铁及其孕育变质处理方法

Also Published As

Publication number Publication date
NO131301C (fr) 1975-05-07
BE785431A (fr) 1972-12-27
LU63431A1 (fr) 1973-01-22
FI60241B (fi) 1981-08-31
DE2230864B2 (de) 1978-04-20
AU470081B2 (en) 1973-12-13
AU4316372A (en) 1973-12-13
OA04125A (fr) 1979-11-30
JPS527406B1 (fr) 1977-03-02
SE408806C (sv) 1981-03-05
SE408806B (sv) 1979-07-09
BR7204244D0 (pt) 1973-05-24
NO131301B (fr) 1975-01-27
DE2230864A1 (de) 1973-01-18
ZA723826B (en) 1974-02-27
DE2230864C3 (de) 1978-12-14
GB1390011A (en) 1975-04-09
CA990105A (fr) 1976-06-01
IT959133B (it) 1973-11-10
FI60241C (fi) 1981-12-10

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