Abstract: An extra-low carbon cold rolled steel sheet useful for use in automobiles and the like, having an improved spot weldability is obtained by combining and adding Ti, Nb and B in predetermined amounts to an extra-low carbon steel to control the amount of fine Ti precipitate dispersed in steel to within a specified reasonable range. Furthermore, the spot weldability is improved by controlling the production conditions of the extra-low carbon steel sheet to within specified reasonable ranges.

Abstract: An extra-low carbon cold rolled steel sheet useful for use in automobiles, and the like, having an improved spot weldability is obtained by combining and adding Ti, Nb and B in predetermined amounts to the extra-low carbon steel to control the amount of fine Ti precipitate dispersed in steel to within a specified reasonable range. Furthermore, the spot weldability is improved by controlling the production conditions of the extra-low carbon steel sheet to within specified reasonable ranges.

Abstract: A method of manufacturing formable as-rolled thin steel sheets having excellent ridging resistance and other properties is disclosed, which comprises rolling a low carbon steel to a given thickness without cold rolling and recrystallization annealing steps. In this rolling, at least one rolling pass is carried out within a given temperature range at high draft and high strain rate.

Abstract: A cold-rolled steel sheet for deep drawing having an improved bake hardenability is disclosed, which comprises 0.005-0.015 wt% of C, not more than 1.0 wt% of Si, not more than 1.0 wt% of Mn, not more than 0.15 wt% of P, 0.0005-0.10 wt% of Al, not more than 0.003 wt% of S and not more than 0.004 wt% of N provided that S+N is not more than 0.005 wt%, and Ti satisfying 1.ltoreq.Ti*/C.ltoreq.20, in which Ti* (%)=Ti(%)-48/14N(%)-48/32S(%). Such a cold-rolled steel sheet is obtained by continuously annealing the steel sheet after the cold rolling, provided that a residence time over a temperature region above recrystallization temperature is within 300 seconds.

Abstract: Thin steel sheets having an improved processability are produced when a steel sheet or cast strip obtained through a continuous casting or strip caster process is subjected to a lubrication rolling step at a temperature of from Ar.sub.3 transformation point to 300.degree. C. and a rolling speed of not less than 1,500 m/min. By this method, the cold rolling step or cold rolling-annealing step can be omitted.

Abstract: A cold rolled steel sheet or plated steel sheet having an improved press formability as well as excellent phosphatability, resistance to galling and spot weldability is produced by controlling a surface roughness pattern of the steel sheet so as to satisfy a center-line average surface roughness of 0.3-2.0 .mu.m and a regularity parameter in at least one direction of not more than 0.25 defining the regularity of surface roughness.

Abstract: A cold-rolled steel sheet for deep drawing having an improved bake hardenability, which comprises 0.005-0.015 wt % of C, not more than 1.0 wt % of Si, not more than 1.0 wt % of Mn, not more than 0.15 wt % of P, 0.005-0.10 wt % of Al, not more than 0.003 wt % of S and not more than 0.004 wt % of N provided that S+N is not more than 0.005 wt %, and Ti satisfying 1.ltoreq.Ti*/C.ltoreq.20, in which Ti*(%)=Ti(%)-(48/14)N(%)-(48/32)S(%). Such a cold-rolled steel sheet is obtained by continuously annealing the steel sheet after the cold rolling, provided that a residence time over a temperature region above recrystallization temperature is within 300 seconds.

Abstract: A process for producing a formable thin steel sheet excellent in ridging resistance. Said process comprises finishing a low carbon steel at a strain rate of not less than 300 (s.sup.-1) in a temperature range of 800.degree. to 300.degree. C. in at least one pass when the low carbon steel is rolled into a specified thickness, and subsequently performing recrystallization annealing.

Abstract: An improved wire with an excellent adhesion with rubber is disclosed for reinforcing rubber goods, made by a diffusion process wherein oxides formed on the surface of plated metal during diffusion are removed before drawing.