Mold steel for long life cycle die casting having high hardenability and superior nitriding property

• Main Authors: KIM BYOUNG KOO, KIM KUK CHEOL, KIM JEONG WOOK, JEONG JAE SUK
• Format: Patent
• Language: English; Korean
• Published: 03.09.2019
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The present invention relates to a hot-work mold steel comprising: 0.37 to 0.46 wt% of carbon (C), 0.25 to 0.5 wt% of silicon (Si), 0.36 to 0.56 wt% of manganese (Mn), 2.0 to 5.0 wt% of chromium (Cr), 1.4 to 2.6 wt% of molybdenum (Mo), 0.4 to 0.8 wt% of vanadium (V), 0.0007 to 0.004 wt% of boron (B), 0.002 to 0.022 wt% of aluminum (Al), 0.001 to 0.09 wt% of titanium (Ti), and the remainder of iron (Fe) and inevitable impurities, and a manufacturing method therefor. The hot-work mold steel exhibits excellent thermal conductivity, hardenability, durability, and nitriding properties, thereby increasing resistance to heat check and melt-out. When a die-casting mold is manufactured by using such a hot-work mold steel, the die-casting mold has improved thermal conductivity regardless of mold size. Further, the life of the mold is extended, and parts manufactured by using the mold can have improved surface quality. 탄소(C) 0.37 ~ 0.46 중량%, 규소(Si) 0.25 ~ 0.5 중량%, 망간(Mn) 0.36 ~ 0.56 중량%, 크롬(Cr) 2.0 ~ 5.0 중량%, 몰리브덴(Mo) 1.4 ~ 2.6 중량%, 바나듐(V) 0.4 ~ 0.8 중량%, 붕소(B) 0.0007 ~ 0.004 중량%, 알루미늄(Al) 0.002 ~ 0.022 중량%, 티타늄(Ti) 0.001 ~ 0.09 중량%, 나머지는 철(Fe) 및 불가피한 불순물을 포함하는 열간 금형강 및 이의 제조방법에 관한 것으로, 상기 열간 금형강은 열전도도, 경화능, 내구성 및 질화특성이 우수하여 히트체크 및 용손에 대한 저항성을 향상되며, 이러한 열간 금형강을 이용하여 다이캐스팅 금형을 제조하는 경우 금형의 크기와 상관 없이 향상된 열전도도를 갖는다. 또한 금형의 수명을 연장시킬 수 있으며, 이러한 금형을 사용하여 제조된 부품의 경우에는 표면 품질이 향상될 수 있다.