Abstract: In a method of laser emission spectroscopical analysis, wherein a light emitted from the surface of a sample when a laser beam is irradiated onto the surface of the sample is spectroscopically analyzed, an emission mode of the laser beam is fixed to a gauss distribution type TEM.sub.00 mode to avoid variations in an intensity distribution due to a change in mode, and an analyzed value is obtained from an intensity of a spectral line of an element to be measured when an intensity of a preset spectral line or an intensity ratio between a pair of preset spectral lines is within a predetermined range, so that the influence of wide fluctuations in an evaporation and an excitation processes occurring on the surface of the sample can be eliminated, thereby improving the accuracy of analysis.

Abstract: The present invention provides a method for producing a thin cold rolled steel sheet, which is adapted to be formed into, for example, an external automotive plate. The method includes an appearance-finishing step by bake-coating as a final step after drawing (such as press molding), and has a remarkably high baking hardenability. The baking hardenability is a property for improving the yield strength due to the heating during the bake coating treatment and is particularly advantageous for producing a light weight automobile and for compensating the deterioration of dent resistance of the automotive plate due to the lowering of its weight, (without deteriorating the r value). The latter is an indication of the press moldability of the thin steel sheet. Furthermore, the present invention discloses an effective compounding amount of Ti which acts to fix C, S and N contained in the steel, and a continuous annealing condition properly selected depending upon the effective amount of Ti.

Abstract: A pretreatment of cold-rolled steel sheet for annealing so as to suppress graphite formation on the surface thereof and nitrogenization during the annealing for recrystallization, by causing an effective amount of sulfur, aluminum, tin, arsenic, lead, antimony, bismuth, selenium, and/or tellurium to exist on the steel sheet surface.

Abstract: A pretreatment of cold-rolled steel sheet for annealing so as to suppress graphite formation on the surface thereof and nitrogenization during the annealing for recrystallization, by causing an effective amount of sulfur, aluminum, tin, arsenic, lead, antimony, bismuth, selenium, and/or tellurium to exist on the steel sheet surface.