PURPOSE: To prevent weld cracking, by casting a stainless steel contg. Cr, Ni and Mn and having its Ms point close to room temp. and its Mf point below room temp. into a rough body for the runner of a water turbine, retouching and welding the rough body at a temp. above the Ms point, and subjecting it to normalizing, subzero treatment and tempering.
CONSTITUTION: A stainless steel contg., by wt., 11W14% Cr, 0.5W8% Ni, 2W9% Mn, <0.1% C and <1% Si and having its Ms point close to room temp. and its Mf point below room temp. is melted. The molten steel is cast into a rough body for the runner of a water turbine. The rough body is retouched and welded at a temp. above the Ms point of the steel, and it is subjected to normalizing, subzero treatment and tempering.
YAMAMOTO MASAO
KAWAI MITSUO
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