JP2010024481A5 - - Google Patents

Description

First, as a preliminary experiment that assumes direct quenching disclosed in Case 6, when a red hot wire made into a bundle of 10 or more is submerged slowly in a cold water tank in a horizontal state, it is cooled while boiling, and is not necessarily rapidly cooled. It was confirmed that it should not. The following results from the experiment: In this method, the coolant water flows in a horizontal centrifugal radial manner in the upper layer of the cooling tank. The stacking table slowly descends at a speed equivalent to the stacking speed (about 1 to 2 cm / s in the upward stacking speed). As the lump of red-hot rod rings begins to immerse, the water surface boils and waves. For this reason, the cooling at the initial stage of immersion is not rapid cooling, and is slow and uneven. This is not a problem with steels with high hardenability, but carbon steel with low hardenability partially induces incomplete hardening. Details of this phenomenon will be described later.

The effect of water temperature is extremely large in water quenching. Although it is 40 degrees C or less as a definition of cold water, it is more desirable to control to 30 degrees C or less. In addition, since the flow velocity also affects, a mechanism that does not cause a large difference in each part of the ring is necessary. In Patent Document 6 of Case 6, an appropriate refrigerant circulation system is described in detail, and this method is used in the present invention. That is, a large amount of cold water is supplied from the water supply port 13 at the center bottom of the cold water tank 12, the inside of the inner cylinder 14 is raised, and the upper layer of the tank 12 is discharged radially and uniformly in the tangential direction from the inner cylinder 14. FIG. 3C is an explanatory view of a state in which the uniformly discharged water flow is rotated by the rotation of the accumulation table to form a uniform horizontal centrifugal radial flow 15. The water supply is discharged from a discharge port 16 provided at the upper edge of the cold water tank 12, and the water level becomes constant.

Claims (4)

  A method of direct quenching of a hot-rolled steel bar wire, wherein the hot-rolled bar wire after finish rolling is formed into a vertical spiral ring row by passing through a spiral guide tube that rotates about a vertical axis, The ring rows are dropped on a horizontal stacking table and stacked, and by rotating the stacking table about the center axis of the ring row and the eccentric axis, the trajectories of the centers of the individual rings are sequentially spaced at equal intervals. In the method of forming a coil that accumulates in a circular pattern, the stacking table is immersed in the upper layer part in a cold water tank having a horizontal centrifugal radial flow in the upper layer part and waited, and the accumulation part is kept below the surface of the water. A direct quenching method for rods, characterized in that the entire circumference and the entire length of the ring row are water-quenched evenly by maintaining them at a standard level.   2. The method of directly quenching a bar wire according to claim 1, wherein the depth of the accumulation portion is set to a constant value not less than 30 mm and not more than 300 mm downward from the water surface.   The method of directly quenching a bar wire according to claim 1 or 2, wherein the bar wire immediately after finish rolling is passed through a water-cooling device and precooled to suppress recrystallization and subsequent grain growth.   A method for forming a vertical spiral ring array is to form a non-concentric series horizontal by forming a red hot rod wire after finish rolling into a spiral ring array by a laying winder and then dropping the ring array onto a conveyor that runs horizontally. 4. The bar according to claim 1, 2 or 3, wherein the rod is deformed into a ring row, and then the horizontal ring row is ejected horizontally at the conveyor end and dropped into a vertical spiral ring row. Direct quenching method for wires.