Back to results
US 3,937,448 AGranted
Apparatus for hardening steel pipes
AssigneeSumitomo Metal Industries, Ltd.
InventorsYoshihisa Fujii, Akio Fujiwara
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeSumitomo Metal Industries, Ltd.
InventorsYoshihisa Fujii, Akio Fujiwara
Estimating the term…
This invention relates to an apparatus wherein the setting angles of cooling water jetting orifices and an outer quenching head and an inner quenching head are made 30.degree..+-.10.degree. in the pipe advancing direction with the pipe axis, and the number of jetting orifices of the inner quenching head are greater for purposes of higher density for the front 1/3 of the length of the head and lower for purposes of lower density for the rear 2/3 of the length of the head. Further, the first contact point of inner quenching water within the inner surface of the pipe is so set as to be delayed by 20 to 150mm. from the first contact point of quenching water with the outer surface of the pipe, the outer quenching being carried out when the steel pipe heating temperature is above the A.sub.3 transformation point and the inner quenching is carried out when the temperature of the inner surface of the pipe is just below the A.sub.1 transformation point. As both heads have a fixed angle, water or steam will not enter the unquenched part and the quenching velocity and the hardness of the cross-section of the steel pipe will be improved.
An apparatus for hardening steel pipes, comprising an inner quenching head mounted for movement in a longitudinal direction of the pipe, an outer quenching head fixedly mounted on a base member, said quenching heads having quenching water jetting orifices inclined at angles of 30.degree. .+-. 10.degree. to an advancing direction of the pipe axis, a water supply boom fixed to said inner quenching head, means for moving said boom in the longitudinal direction of the pipe, means for holding and centering said inner quenching head along the longitudinal axis of the pipe, said moving means comprising a movable stand and a carriage means for movement parallel to the longitudinal axis of the pipe, said boom being connected to said moving means, and said stand having means thereon for bearing against said boom for moving same in a direction at right angles to the pipe axis.
Dependencies are inferred from the claim text.