Abstract: A continuous annealing and pickling process of flat cold-rolled products, such as stainless steel strips, to obtain a high surface quality product at high production rates and with a low environmental impact. It comprises the following steps: heating, up to a temperature comprised in the range 650-1050° C., in an atmosphere with an oxygen content comprised in the range from 0.5 to 12%; heating for a time comprised from 10 to 200 sec up to a temperature comprised in the range from 650 to 1200° C. in presence of oxidizing agents and/or inert agents; cooling down to temperatures comprised in the range from 650° C. to ambient temperature in presence of oxidizing agents and/or inert agents; thermochemical or electrolytic descaling and finally possible pickling and/or passivation, by means of the use of pickling baths consisting of mineral acid solutions.

Abstract: Environment-friendly process for descaling, pickling and finishing/passivating in a continuous, integrated and flexible manner, applicable to any type of stainless steel, regardless of its physical structure, chemical composition and nature of surface oxides to be removed, within a single plant in which the required chemical, electrochemical, mechanical and hydromechanical treatments are carried out, merely diversifying the operative conditions of each treatment according to the stainless steel type to be processed. The process and the plant according to the invention allow elevated reaction rate, excellent surface quality, low energy and chemical reagent consumption and total environmental compatibility. The figure shows the block diagram of an embodiment of the plant according to the invention.

Abstract: A continuous annealing and pickling process of flat cold-rolled products, such as stainless steel strips, to obtain a high surface quality product at high production rates and with a low environmental impact. It comprises the following steps: heating, up to a temperature comprised in the range 650-1050° C., in an atmosphere with an oxygen content comprised in the range from 0.5 to 12%; heating for a time comprised from 10 to 200 sec up to a temperature comprised in the range from 650 to 1200° C. in presence of oxidizing agents and/or inert agents; cooling down to temperatures comprised in the range from 650° C. to ambient tempera in presence of oxidizing agents and/or inert agents; thermochemical or electrolytic descaling and finally possible pickling and/or passivation, by means of the use of pickling baths consisting of mineral acid solutions.

Abstract: Environment-friendly process for descaling, pickling and finishing/passivating in a continuous, integrated and flexible manner, applicable to any type of stainless steel, regardless of its physical structure, chemical composition and nature of surface oxides to be removed, within a single plant in which the required chemical, electrochemical, mechanical and hydromechanical treatments are carried out, merely diversifying the operative conditions of each treatment according to the stainless steel type to be processed. The process and the plant according to the invention allow elevated reaction rate, excellent surface quality, low energy and chemical reagent consumption and total environmental compatibility. The figure shows the block diagram of an embodiment of the plant according to the invention.

Abstract: Continuous electrolytic pickling method for steels, Nickel, superalloys, Titanium and alloys thereof, characterised in that the material to be treated , for a time comprised between 3 sec and 60 sec, is immersed into or passes through at least one electrolytic cell with an electrolytic solution consisting of a neutral or acid aqueous solution, at a temperature comprised between 20 DEG C. and 95 DEG C., with at least one pair of electrodes connected to an alternate current power supply having a frequency ranging from 1 Hz to 1000 Hz, the electrolysis being carried out at a current density having an effective amplitude ranging from 10 A/dm2 to 250 A/dm2. The Figure depicts the progress of the weight loss of an AISI 409 (X6CrTil2) steel as a function of the application time of an embodiment of the pickling method according to the present invention.