25-07-2013 дата публикации
Номер: US20130186159A1
Rolling mill shear provided with at least one blade having characteristics of toughness and resistance to thermal shock typical of the family of tool steels for hot shearing and at the same time having sufficiently high characteristics of surface hardness and wear resistance, typical of tool steels for cold shearing. This shear is particularly suitable for carrying out, with greater efficiency and for a longer time, relative to the known shears, the shearing of sections or bars at a temperature between 150 and 800° C., downstream of the Quenching & Tempering heat treatment thereof. 1. Shear for rolling mill having at lease one blade made of steel whose chemical composition , in mass percentage , consists of 0 ,4S-0 ,55% carbon. 0 ,10-0 ,30% silicon , 0 ,20-0 ,50% manganese , 4 ,00-5 ,50% chromium , 2 ,00-3 ,00% molybdenum , 0 ,45-0 ,65% -vanadium and the remainder being iron and inevitable impurities , and whose microstruture is composed of tempered martensite.2. Use of a shear according to in a rolling mill claim 1 , wherein said shear is arranged downstream of a quenching and tempering machine and upstream of a cooling plate.3. Use of a shear according to claim 2 , wherein said shear is arranged downstream of the quenching and tempering machine without further intermediate devices between said quenching and tempering machine and said shear.4. A production claim 1 , process for producing a blade of a shear according to claim 1 , comprising the following steps:providing a first steel ingot whose chemical composition, in mass percentage, consists of 0,45-0,55% carbon, 0,10-0,30% silicon, 0,20-0,50% manganese, 4,00-5,50% chromium, 2,00-3,00% molybdenum- 0,45-0,65% vanadium and the remainder being iron and inevitable imparities;providing electro-slag-remelting of said first ingot and obtaining a second newly solidified ingot;providing rolling of said second ingot until obtaining a blade blank having a predetermined shape;providing a quenching cycle consisting in ...
Подробнее