Sumitomo Metal Industries, Inc.

Hiroo Ohtani

Yasutaka Okada

Akio Ikeda

Takeo Kudo

Kunihiko Yoshikawa

Taishi Moroishi

Seiichi Watanabe

Yoshiro Matsumoto

Toshiji Takigawa

Tatsuro Kunitake

A process for manufacturing high strength deep well casing, tubing, and drill pipes, which have improved resistance to stress corrosion cracking is disclosed. The process comprises the steps of preparing an alloy composition which is:

Process for making high strength deep well casing and tubing having

An alloy useful for manufacturing high strength deep well casing, tubing and drill pipes for use in oil-well operations is disclosed. The alloy exhibits improved resistance to stress corrosion cracking in the H.sub.2 S--CO.sub.2 --Cl.sup.- environment, which comprises the following alloy composition:

Alloy for making high strength deep well casing and tubing having

An alloy useful for manufacturing high strength deep well casing, tubing and drill pipes for use in oil-well operations is disclosed. The alloy exhibits improved resistance to stress corrosion cracking in the H.sub.2 S--CO.sub.2 --Cl.sup.- -environment, which comprises the following alloy composition:

An alloy useful for manufacturing high strength deep well casing, tubing and drill pipes for use in oil-well operations is disclosed. The alloy exhibits improved resistance to stress corrosion cracking in the H.sub.2 S-CO.sub.2 -Cl.sup.- environment, which comprises the following alloy composition:

An alloy useful for manufacturing high strength oil-well casing, tubing and drill pipes for use in oil-well operations is disclosed. The alloy exhibits improved resistance to stress corrosion cracking in the H.sub.2 S--CO.sub.2 --Cl.sup.- environment, which comprises the following alloy composition:

Chromium-molybdenum structural steels which have high tensile strength, low susceptability to temper embrittlement, high hydrogen attack resistivity and high temperature ductility and which can be formed into very thick steel plates comprise 0.05 to 0.20% of C, 0 to 0.15% of Si, 0.46 to 1.00% of Mn, 2.00 to 3.50% of Cr, 0.80 to 1.20% of Mo, 0.00015 to 0.0015% of B, 0.005 to 0.070% of Sol. Al and inevitably entrained impurities, the balance to make up 100% of Fe. Preferably the inevitably entrained impurities of nitrogen and phosphorus are below 0.0060% of N and 0.0010% of P.

Method of making steels which are useful in fabricating pressure vessels

Chromium-molybdenum steels which have high strengths, good hydrogen attack resistivities, good high-temperature ductilities and high creep rupture strength, and which, when formed into steel plates, welded and given a high-temperature strain relief annealing treatment will acquire high resistivity to creep damage, comprises 0.11 to 0.17% of C, 0.50 to 1.20% of Si, 0.46 to 1.00% of Mn, 1.00 to 1.50% of Cr, 0.45 to 0.65% of Mo, 0.00015 to 0.0015% of B, 0.010 to 0.100% of Sol. Al and inevitably entrained impurities, the balance to make up 100% of Fe. Preferably the inevitable nitrogen and phosphorus impurities are kept below 0.0060% of N and 0.010% of P.

Steels which are useful in fabricating pressure vessels

A heavy thick steel casting having high mechanical strength with a tensile strength of 80 kg/mm.sup.2 or more, excellent impact properties with a vE.sub.O value of more than 8 kg-m/cm.sup.2 and improved weldability, and also a method of manufacturing the same. In the method, steel containing boron as an essential component and with a Ceq value corresponding to the maximum thickness of the product is cast. The casting is solidified in air, then heated to a temperature of 930.degree. to 1,050.degree. C. for one hour or more, followed by air cooling. Thereafter, the casting is quenched and tempered to thereby impart the casting with the desired characteristics.

Growing community of inventors

Kobe, Japan

Hiroo Ohtani