Excellent weldability steel thick wall material and its mfg. method

Application Number: 00102663
Application Date: 2000.02.25
Publication Number: 1297063
Publication Date: 2001.05.30
Priority Information: 1999/2/25 JP 048962/1999
International: C21D8/00
Applicant(s) Name: National Research Inst. for Metal
Inventor(s) Name: Nakajima Hiroshi;Toritsuka Shiro;Tsusaki Kaneaki
Patent Agency Code: 11038
Patent Agent: yang hongjun
Abstract A tough high strength heavy wall steel material having superior weldability is provided, said steel material has a diameter or a side 5 mm or more in length, and comprises oxides 1 mum or less in particle diameter homogeneously dispersed at a dispersion density in a range of from10,000 to 100,000 particles/mm<2> and uniform ferrite grains 2 mum or less in grain diameter formed over the entire plane making a right angle with respect to the rolling direction.