PURPOSE: To let it have excellent toughness without the need for reheating treatment after hot forging by adding Ti in a specific amount to steel in relation to S and N contained in structural steel for machinery.
CONSTITUTION: A molten structural steel for machinery, containing 0.25 to 0.7% C, 0.15 to 0.35% Si, 0.3 to 2% Mn, and one or more of 0.2 to 1.0% Cr, 0.1 to 0.5% Mo, and 0.4 to 2.0% Ni, is sufficiently deoxidized by Ca, Mg, REM, etc., and then 0.005 to 0.03% Ti enough to satisfy S and N contained as impurities and the following formula is added to the molten steel; that is, Ti/(3S+N)=0.4 to 1.0. The steel, in which the growth of crystals is suppressed and also low temperature toughness is raised even when it is forged at a high temperature of approx. 120°C, is applicable to steel material for hot processing which is usable without reheating treatment for reaustenitizing.
MIKI TAKESHI
TSUCHIDA YUTAKA
AKAZAWA MASAHISA
| JPS52131918A | 1977-11-05 | |||
| JPS5143312A | 1976-04-14 | |||
| JP51158521A | ||||
| JPS5324888A | 1978-03-08 | |||
| JPS52115719A | 1977-09-28 |