| 摘要 |
<p>PURPOSE: A low specific gravity alloy and a method for manufacturing the same are provided to improve yield strength at over 10% against an existing low specific gravity alloy system through precipitation strengthening. CONSTITUTION: A low specific gravity alloy includes Fe as a main component, 10 to 20 wt% of Al, 5 to 20 wt% of Mn, 0.5 to 1 wt% of C, 1 to 3 wt% of Cr, 1 to 3 wt% of Si, 2 to 4 wt% of Mg, below 0.02% of P(excluding 0%), below 0.01% of S(excluding 0%), and other inevitable impurities. The specific gravity of the alloy is 6.8g/cm^3 or less(excluding 0g/cm^3). A method for manufacturing the alloy includes: a step of raising the temperature of molten metal having Fe as a main component, and then adding 0.5 to 1 wt% of C to the molten metal; a step of adding 5 to 20 wt% of Mn, 1 to 3 wt% of Cr, and 1 to 3 wt% of Si to the molten metal; a step of charging a master alloy comprising 10 to 20 wt% of Al and 2 to 4 wt% of Mg to the molten metal; and a step of cooling the molten metal after charging the master alloy. [Reference numerals] (AA) Temperature rise; (BB) C added; (CC) Cr, Si, and Mn added; (DD) Al-20 wt% Mg charged, maintained for 30 min</p> |
