摘要:
A method for continuously tin-electroplating a metal strip, which comprises the steps of: causing a DC electric current to flow between a metal strip and an anode arranged adjacent to the metal strip while passing the metal strip at a travelling speed of at least 1 m/minute through an acidic tin-electroplating solution containing tin ions and an organic acid within a range of from 4.8 to 98 g/l as converted into sulfuric acid, to form a tin-electroplating layer on at least one surface of the metal strip; and applying an ultrasonic vibration, emitted from at least one ultrasonic vibrator and having an intensity within a range of from 0.01 to 1,000 W/100 cm.sup.2 and a frequency within a range of from 25 to 55 kHz, to the acidic tin-electroplating solution between the metal strip and the anode, thereby removing a diffusion layer of tin ions existing in the acidic tin-electroplating solution adjacent to the surface of the metal strip.
摘要:
A method for manufacturing a tin-electroplated cold-rolled steel strip, which comprises the steps of: continuously annealing a degreased cold-rolled steel strip; then, subjecting, following the continuous annealing treatment, the continuously annealed cold-rolled steel strip to a continuous tin-electroplating treatment in a tin-electroplating bath to form, on at least one surface of the cold-rolled steel strip, a tin-electroplating layer having a plating weight within a range of from 0.1 to 2.8 g/m.sup.2 per surface of the cold-rolled steel strip; and then, temper-rolling, following the continuous tin-electroplating treatment, the cold-rolled steel strip having the tin-electroplating layer on at least one surface thereof, at a reduction ratio within a range of from 1 to 5%.
摘要:
An additive for an acidic tinplating bath comprises: an additive ingredient (A) prepared by adding oxypropylene to polyoxyethylene glycol and having an average molecular weight ranging from 3000 to 18000; an additive ingredient (B) prepared by adding oxypropylene to polyoxyethylene glycol and having an average molecular weight ranging from 300 to 1500; and the additive ingredient (A) and the additive ingredient (B) having a weight ratio of the additive ingredient (A) to the additive ingredient (B) being from 97/3 to 40/60.
摘要:
According to one aspect of the present invention, there is provided a process of fabricating a steel material by performing a heat treatment to a steel material having high strength, in order to reduce hardness at one part of the steel material to less than hardness at other parts of the steel material, wherein the heat treatment comprises a heating step in which a portion having a certain depth from a surface of the steel material is rapidly heated by induction heating or direct energization heating, and a cooling step in which the steel material, which has been subject to the heating step, is rapidly cooled a predetermined time after the heating step, and a heating temperature in the heating step is Ac1 transforming point or more.