| 摘要 |
<p>PURPOSE: A steel sheet for an anti-abrasive with excellent low-temperature toughness and weldability and a manufacturing method thereof are provided to improve weldability and low-temperature toughness by optimizing a steel composition and a manufacture condition. CONSTITUTION: A steel sheet for an anti-abrasive with excellent low-temperature toughness and weldability comprises 0.05-0.18% of C, 0.15-0.3% of Si, 0.5-1.5% of Mn, 0.1-1.0% of Cr, 0.1-0.5% of Mo, 0.1-0.5wt% of Ni, 0.0005-0.0050% of B, 0.01-0.03% of Ti, 0.01-0.05% of Nb, 0.005-0.1% of Sol.Al, less than 0.015% of P, and less than 0.010% of S as a weight%, and a rest comprises Fe and an unavoidable impurity. A Ceq. value (Ceq.= C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15) is less than 0.50. A primary austenite grain particle size (AGS) is more than 8 based on an ASTM E112 and less than an average 20μm. A base micro-structure has a martensite structure more than 90 volume% including a minute coal/nitride in an inside. [Reference numerals] (AA,FF,JJ) Temperature; (BB,GG,KK) Re-heating; (CC,LL) Air cooling; (DD) Quenching; (EE,II,MM) Time; (HH) Direct quenching (1st Q)</p> |
