Republic Steel Corporation

George M Waid

Anthony T Davenport

Joseph E Franklin

Dionisyj W Demianczuk

Robert T Ault

For skelp to make pipe having a seam butt-joined as by electrical resistance or submerged arc welding, skelp is made by pouring a base melt of rimming steel into an ingot mold to about 80 to 95% full and then after a shell of rimmed steel has solidified against the mold wall, completing pouring of the same melt while adding further material to the molten core, e.g. more C or Mn, and Al or the like for killing, so that the solidified ingot has a core of desired high strength, killed or semi-killed steel. The ingot is processed to desired skelp by hot rolling, the top and bottom regions being suitably cropped, so that the skelp has a main body of the high strength steel, bordered lengthwise by integral edge zones, e.g. 1/2 inch or more wide, of the rimmed steel, free of unwanted inclusions. When rolled to pipe shape, with finished edges, the edge zones are electrically butt welded, such operation being effected with unusual facility. In the completed pipe, the weld region is relatively free of oxide or like inclusions, and thus not susceptible of rejection for defects at or about the seam, while the pipe is essentially characterized by high wall strength.

Manufacture of electrically welded steel pipe

Process of making as-pierced tubular steel casing having a yield strength of 80-110 ksi, a minimum tensile strength of 100 ksi, and a minimum elongation of 121/2% in two inches. The steel is stengthened by precipitation of vanadium carbides, including carbonitrides, and has a ferrite-pearlite microstructure with a ferrite grain size of about ASTM 7 or finer.

Method of making as-pierced tubular products

A welded tubular steel product having a high ultimate tensile strength of at least 95 ksi and a relatively low yield strength in a range of from 55 to 80 ksi is made by alloying a plain carbon-manganese steel solely with chromium.

Welded alloy casing

Steel well casing having the combined properties of excellent resistance to hydrogen sulfide stress corrosion and high yield strength ranging upward from 90,000 to 145,000 psi comprised of an aluminum-killed steel alloyed with chromium, molybdenum and vanadium. The casing is quenched to martensite from an austenitizing temperature in the range of from 1550.degree. to 1700.degree. F. and is tempered in the range of from 1200.degree. to 1400.degree. F. to a maximum hardness of 35 R.sub.C.

Growing community of inventors

Burton, OH, United States of America

George M Waid