Inland Steel Company

William E Heitmann

Prabhat K Rastogi

Thomas G Oakwood

Birchel S Brown

Richard J Sulewski

A billet of steel has a composition comprising small amounts of hardenability agents. The billet is hot rolled into a continuous bar, in two hot rolling stages with an intervening cooling step employing a turbulent cooling liquid. After the second hot rolling stage, the bar is gathered into a succession of closely overlaying loops and moved along a roller conveyor where the overlapping loops are cooled by air blowers, after which the bar is coiled. The resulting hot rolled bar has a microstincture consisting essentially of bainite in fine-sized packets reflecting an average austenitic grain size, before the gathering and cooling steps, of 8-11 ASTM. A threaded fastener in its final form can be produced from the hot rolled bar by a cold deforming operation without a heat treating operation before or after cold deforming. The threaded fastener is undistorted and contains residual compressive stresses.

Cold deformable, high strength, hot rolled bar and method for producing

A hot rolled steel bar is subjected to controlled hot roll finishing and cooling conditions which, together with the composition of the steel and controlled subsequent heat treating and quenching conditions, enable the formation of a steel spring having both relatively high hardness and high toughness.

Steel spring and method for producing same

Steel bar and method for producing same

A hot rolled, high strength, low alloy steel strip is prepared from a steel having a controlled composition employing small quantities of Cb and V, and the steel is renitrogenized. Deliberate Si addition is avoided. The carbon and manganese contents are controlled, and a sulfur controlling agent is employed. Hot rolling practice is controlled. The hot rolled steel strip has a microstructure consisting essentially of a ferrite matrix with scattered pearlite, a relatively fine ferrite grain size and excellent yield strength and ductility.

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Crown Point, IN, United States of America

William E Heitmann