Sumitomo Chemical Company, Limited

Nippon Stainless Steel Co., Ltd.

Masaaki Nagayama

Masahiro Aoki

Masao Okubo

Takeshi Yoshida

Kiichi Saito

Noriyasu Ikeda

Masayoshi Miki

Masanori Takahashi

Mineo Kobayashi

This invention relates to a manufacturing process for plate or forging (bar, stamp work or the like) of ferrite-austenite two-phase stainless steel, containing C at 0.03% or below, Si at 2.0% or below, Mn at 2.0% or below, Cr at 25 to 35%, Ni at 6 to 15%, N at 0.35% or below, and Fe and inevitable impurity for the remainder with or without adding B at 0.001 to 0.030% with the following nickel balance value specified at -3 to -9 and comprising an average crystal grain size at 0.015 mm or below from heating an ingot of the above mentioned ferrite-austenite two-phase stainless steel at 1,200.degree. C. or below and keeping a forging ratio by hot working at 5 or over.

Manufacturing process for plate or forging of ferrite-austenite

This invention relates to a welding material for welding a high-Si austenite stainless steel, capable of ensuring a high corrosion resistance of the weld metal in hot nitric acid of high concentration, while maintaining a toughness of the weld metal not smaller than 2 Kg-m/cm.sup.2, and the method of application therefor. The welding material has a composition containing not greater than 0.015% of C, 5 to 7% of Si, not greater than 2% of Mn, 15 to 20% of Cr, 10 to 22% of Ni, not greater than 0.02% of N, not greater than 0.45% of one or both of Nb and Ta, and the balance substantially Fe and inevitable impurities the sum of C and N contents is selected to be not greater than 0.03% and the sum of Nb and Ta contents is selected to be not smaller than 15.times.(C+N)%. The Ni-balance value given by the following formula ranges between -4 and -2.

Welding material for austenite stainless steel having high Si content

This invention relates to a welding material of ferrite-austenite two-phase stainless steel capable of producing a weld metal having a high resistance to corrosion, particularly in an environment containing nitric acid, and the method of application therefor. The welding material consists essentially of not more than 0.03% of C, not more than 2.0% of Si, not more than 2.0% of Mn, 25 to 30% of Cr, 7 to 12% of Ni, not more than 0.35% of N, and the balance Fe and inevitable impurities. The Ni balance value given by the following formula ranges between -11.7 and -6.7:

Welding material of ferrite-austenite two-phase stainless steel and

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Niihama, Japan

Masaaki Nagayama