ROLLED H-SHAPED STEEL HAVING UNIFORM MICROSTRUCTURE AND UNIFORM MECHANICAL PROPERTIES AND METHOD FOR PRODUCING THE SAME

摘要

The present invention relates to an H-section used as a member for building structures, and in particular, is a rolled H-section having uniform microstructures and uniform mechanical properties, and a method of producing the same, characterized in that: the microstructures satisfy any one or more of the following conditions on the basis of a 1/4 flange portion in a cross section of said H-section:1) the deviations of the average grain sizes of ferrite in the microstructures of a 1/2 flange portion and a fillet portion from that of the 1/4 flange portion are within ± 15% thereof,2) the deviation of the average grain size of ferrite in the microstructure of a 1/2 web portion from that of the 1/4 flange portion is within ± 15% thereof,3) the deviations of the average rates of pearlite in the microstructures of a 1/2 flange portion and the fillet portion from that of the 1/4 flange portion are within ± 8% thereof, and4) the deviation of the average rate of pearlite in the microstructure of a 1/2 web portion from that of the 1/4 flange portion is within ± 8% thereof.