JPS55106602A - Manufacture of steel sheet pile - Google Patents

Abstract

PURPOSE:To prevent the slip-out of the contact part and prevent the generation of cracks in the middle zone of inner side of the pawl, by slightly bending the pawl with the horizontal and vertical rolls before bending pass for forming the joint pawl of the steel sheet pile, and by making rough the surface of inner side of the pawl. CONSTITUTION:The rolled material 52A, whose pawl 56 and web 54 are formed by the second intermediate mill, is sent to the universal mill, etc., and is passed through the caliber 68 formed by upper and lower horizontal rolls 64A, 64B, and the vertical roll 66. At this rolling work, the pawl 56 is bent by a degree smaller than the specified degree of the product, and the web 54 is slightly reduced by rolling. Hereby, the middle zone F of inner side of the pawl, being apt to generate cracks, is formed into a close-packed structure. Besides, scratch flaws are given to the tip of inner side of the pawl by the thin groove 70 installed in the vertical roll 66. Next, the pawls 56, 58, are bent by the third intermediate mill, and the web is slightly reduced by rolling work. Accordingly, the slip-out of the tip of inner side of the pawl and the generation of cracks in the middle zone of inner side, at the setting work for sheet piles, can be prevented, and the joint strength is improved.