Exxon Research and Engineering Company

Other

Michael J Luton

Jayoung Koo

Narasimha-Rao Venkata Bangaru

Clifford W Petersen

Takuya Hara

Hitoshi Asahi

Hiroshi Tamehiro

Yoshio Terada

Joseph Vallone

John P Dismukes

Masahiko Hamada

Ruzica Petkovic-Luton

Yu-ichi Komizo

Shuji Okaguchi

Kazuki Fujiwara

Raghavan Ayer

Stephen Matras

Masaaki Sugiyama

An ultra-high strength steel having excellent ultra-low temperature toughness, a tensile strength of at least about 930 MPa (135 ksi), and a microstructure comprising predominantly fine-grained lower bainite, fine-grained lath martensite, or mixtures thereof, transformed from substantially unrecrystallized austenite grains and comprising iron and specified weight percentages of the additives: carbon, silicon, manganese, copper, nickel, niobium, vanadium, molybdenum, chromium, titanium, aluminum, calcium, Rare Earth Metals, and magnesium, is prepared by heating a steel slab to a suitable temperature; reducing the slab to form plate in one or more hot rolling passes in a first temperature range in which austenite recrystallizes; further reducing said plate in one or more hot rolling passes in a second temperature range below said first temperature range and above the temperature at which austenite begins to transform to ferrite during cooling; quenching said plate to a suitable Quench Stop Temperature; and stopping said quenching and allowing said plate to air cool to ambient temperature.

Ultra-high strength, weldable steels with excellent ultra-low temperature toughness

A method is provided for producing an ultra-high strength steel having a tensile strength of at least about 900 MPa (130 ksi), a toughness as measured by Charpy V-notch impact test at &minus;40&deg; C. (&minus;40&deg; F.) of at least about 120 joules (90 ft-lbs), and a microstructure comprising predominantly fine-grained lower bainite, fine-grained lath martensite, or mixtures thereof, transformed from substantially unrecrystallized austenite grains and comprising iron and specified weight percentages of the additives: carbon, silicon, manganese, copper, nickel, niobium, vanadium, molybdenum, chromium, titanium, aluminum, calcium, Rare Earth Metals, and magnesium. A steel slab is heated to a suitable temperature; the slab is reduced to form plate in one or more hot rolling passes in a first temperature range in which austenite recrystallizes; said plate is further reduced in one or more hot rolling passes in a second temperature range below said first temperature range and above the temperature at which austenite begins to transform to ferrite during cooling; said plate is quenched to a suitable Quench Stop Temperature; and said quenching is stopped and said plate is allowed to air cool to ambient temperature.

Method for producing ultra-high strength, weldable steels with superior toughness

A high-tensile-strength steel having excellent toughness throughout its thickness, excellent properties at welded joints, and a tensile strength (TS) of at least about 900 MPa (130 ksi), and a method for making such steel, are provided. Steels according to this invention preferably have the following composition based on % by weight: carbon (C): 0.02% to 0.1%; silicon (Si): not greater than 0.6%; manganese (Mn): 0.2% to 2.5%; nickel (Ni): 0.2% to 1.2%; niobium (Nb): 0.01% to 0.1%; titanium (Ti): 0.005% to 0.03%; aluminum (Al): not greater than 0.1%; nitrogen (N): 0.001% to 0.006%; copper (Cu): 0% to 0.6%; chromium (Cr): 0% to 0.8%; molybdenum (Mo): 0% to 0.6%; vanadium (V): 0% to 0.1%; boron (B): 0% to 0.0025%; and calcium (Ca): 0% to 0.006%. The value of Vs as defined by Vs&equals;C&plus;(Mn/5)&plus;5P&minus;(Ni/10)&minus;(Mo/15)&plus;(Cu/10) is 0.15 to 0.42. P and S among impurities are contained in an amount of not greater than 0.015% and not greater than 0.003%, respectively. The carbide size in the steel is not greater than 5 microns in the longitudinal direction.

High-tensile-strength steel and method of manufacturing the same

An ultra-high strength boron-containing steel having a tensile strength of at least about 900 MPa (130 ksi), a toughness as measured by Charpy V-notch impact test at &minus;40&deg; C. (&minus;40&deg; F.) of at least about 120 joules (90 ft-lbs), and a microstructure comprising predominantly fine-grained lower bainite, fine-grained lath martensite, or mixtures thereof, transformed from substantially unrecrystallized austenite grains and comprising iron and specified weight percentages of the additives: carbon, silicon, manganese, copper, nickel, niobium, vanadium, molybdenum, chromium, titanium, aluminum, calcium, Rare Earth Metals, and magnesium, is prepared by heating a steel slab to a suitable temperature; reducing the slab to form plate in one or more hot rolling passes in a first temperature range in which austenite recrystallizes; further reducing said plate in one or more hot rolling passes in a second temperature range below said first temperature range and above the temperature at which austenite begins to transform to ferrite during cooling; quenching said plate to a suitable Quench Stop Temperature; and stopping said quenching and allowing said plate to air cool to ambient temperature.

Ultra-high strength, weldable, boron-containing steels with superior toughness

An ultra-high strength essentially boron-free steel having a tensile strength of at least about 900 MPa (130 ksi), a toughness as measured by Charpy V-notch impact test at &minus;40&deg; C. (&minus;40&deg; F.) of at least about 120 joules (90 ft-lbs), and a microstructure comprising predominantly fine-grained lower bainite, fine-grained lath martensite, or mixtures thereof, transformed from substantially unrecrystallized austenite grains and comprising iron and specified weight percentages of the additives: carbon, silicon, manganese, copper, nickel, niobium, vanadium, molybdenum, chromium, titanium, aluminum, calcium, Rare Earth Metals, and magnesium, is prepared by heating a steel slab to a suitable temperature; reducing the slab to form plate in one or more hot rolling passes in a first temperature range in which austenite recrystallizes; further reducing said plate in one or more hot rolling passes in a second temperature range below said first temperature range and above the temperature at which austenite begins to transform to ferrite during cooling; quenching said plate to a suitable Quench Stop Temperature; and stopping said quenching and allowing said plate to air cool to ambient temperature.

Ultra-high strength, weldable, essentially boron-free steels with superior toughness

High strength steel is produced by a first rolling of a steel composition, reheated above 1100.degree. C., above the austenite recrystallization, a second rolling below the austenite recrystallization temperature, water cooling from above AR.sub.3 to less than 400.degree. C. and followed by tempering below the Ac.sub.1 transformation point.

Ultra high strength, secondary hardening steels with superior toughness

High strength steel is produced by a first rolling of a steel composition, reheated above 1100.degree. C., above the austenite recrystallization, a second rolling below the austenite recrystallization temperature, water cooling from above Ar.sub.3 to less than 400.degree. C. and followed by tempering below the Ac.sub.1 transformation point.

A high strength steel composition comprising ferrite and martensite/banite phases, the ferrite phase having primarily vanadium and mobium carbide or carbonitride precipitates, is prepared by a first rolling above the austenite recrystallization temperature; a second rolling below the anstenite recrystallization temperature; a third rolling between the Ar.sub.3 and Ar.sub.1 transformation points, and water cooling to below about 400.degree. C.

High strength dual phase steel plate with superior toughness and

Method for producing ultra high strength, secondary hardening steels

Method of producing high strength dual phase steel plate with superior

A high strength steel composition comprising ferrite and martensite/bainite phases, the ferrite phase having primarily vanadium and niobium carbide or carbonitride precipitates, is prepared by a first rolling above the austenite recrystallization temperature, a second rolling below the austenite recrystallization temperature; cooling between the Ar.sub.3 transformation point and 500.degree. C.; and water cooling to below about 400.degree. C.

Method of preparing a high strength dual phase steel plate with superior

A method for consolidating finely divided diamond particles to produce a substantially fully dense article having improved resistance to wear and cracking. Diamond particles are heated to an elevated temperature for compacting to form the fully dense article. The article is then held at an elevated temperature and time sufficient to rearrange and substantially reduce the dislocations in the article resulting during compacting to achieve a substantially strain-free state in the article. The article is then cooled to room temperature after which it may be given an improved leaching treatment to achieve superior thermal stability.

Method for fabricating fracture-resistant diamond and diamond composite

Disclosed is a method for extruding fine grain aluminum mechanically alloyed powder material such that the resulting extruded product is substantially free of texture, which method comprises extruding a billet of the powder material having a mean grain size less than about 5 microns through a die having an internal contour which conforms substantially to the formula: ##EQU1## where R is the radius of the die contour at any given point x along the major axis of the die orifice from its entry plane, R.sub.o is the radius of the billet, and K is an arbitrary constant.

Method of extruding aluminum-base oxide dispersion strengthened

Disclosed are extruded dispersion strengthened metallic materials which are substantially free of texture as well as a method for producing such materials. The method comprises extruding a billet of dispersion strengthened metallic powder material comprised of one or more metals and one or more refractory compounds said powder material having a mean grain size less than about 5 microns and whose grain size is substantially stable at the extrusion conditions, through a die having an internal contour such that the material is subjected to a natural strain rate which is substantially constant as it passes through the die.

Extrusion die for extruding metallic powder material

Disclosed are extruded dispersion strengthened metallic materials which are substantially free of texture as well as a method for producing such materials. The method comprises extruding a billet of dispersion strengthened metallic powder material comprised of one or more metals and one or more refractory compounds said powder material having a mean grain size less than about 5 microns and whose grain size is substantially stable at the extrusion conditions, through a die having an internal contour such that the material is subjected to a natural strain rate which is substantially constant as it pass through the die.

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Bridgewater, NJ, United States of America

Michael J Luton