Abstract:
본 발명은 고인성 고경도강 합금 및 그 제조 방법에 관한 것으로, 본 발명의 일 측면은, 탄소(C) 0.4 중량% 내지 0.6 중량%, 실리콘(Si) 1.0 중량% 내지 2.0 중량%, 망간(Mn) 0.4 중량% 내지 1 중량%, 크롬 (Cr) 0.3 중량% 내지 0.9 중량%, 몰리브데넘(Mo) 0.1 중량% 내지 0.4 중량% 및 바나듐(V) 0.1 중량% 내지 0.4 중량%를 포함하고, 마르텐사이트 및 베이나이트 복합상 구조를 포함하는, 고인성 고경도강 합금을 제공한다.
Abstract:
PURPOSE: A high temperature backward extrusion method for titanium alloy is provided to obtain optimized lubricating conditions during high-temperature titanium alloy forging by using graphite cloth. CONSTITUTION: A high temperature backward extrusion method for titanium alloy is as follows. If mold temperature is less than 550°C, graphite cloth is applied to a contact surface between a mold/punch and a work piece in order to lubricate and insulate the mold/punch and the work piece. If the mold temperature is 550°C or greater, graphite cloth coated with water glass is applied to the contact surface between the mold/punch and the work piece in order to lubricate and insulate the mold/punch and the work piece.
Abstract:
본 발명은 국방 및 우주항공 재료와 같은 첨단 구조 재료로 사용되는 소재에 관한 것으로, 특히 강도와 파괴인성이 우수한 고함량 Co-Ni계 합금강의 제조 방법 및 상기 제조 방법에 의해 제조된 W함유 Co-Ni계 이차 경화형 합금강에 관한 것이다. 본 발명은 중량 %로, C: 0.23 ~ 0.28%, Cr: 2.00 ~ 3.50%, W: 0.40 ~ 4.05%, Ni: 7.50 ~ 11.05%, Co: 11.00 ~ 13.50%, 잔부 Fe 및 불가피하게 혼입되는 불순물을 함유하는 강재를 진공 유도 용해 및 일렉트로 슬래그 재용해(ESR)를 거쳐 열간 가공 공정을 통해 제조하는 단계와; 상기 강재를 1000 ~ 1200℃의 온도에서 60 ~ 120분간 유지한 후 급랭하는 단계와; 상기 급랭된 강재를 480 ~ 510℃의 온도에서 60 ~ 600분간 시효 처리하는 단계로 이루어진 강도와 파괴인성이 우수한 W함유 이차 경화형 Co-Ni계 합금강의 제조방법과, 상기 제조방법에 의해 제조된 중량 %로, C: 0.23 ~ 0.28%, Cr: 2.00 ~ 3.50%, W: 0.40 ~ 4.05%, Ni: 7.50 ~ 11.05%, Co: 11.00 ~ 13.50%, 잔부 Fe 및 불가피하게 혼입되는 불순물을 함유하는 강도와 파괴인성이 우수한 W함유 이차 경화형 Co-Ni계 합금강을 그 특징으로 한다.
Abstract:
PURPOSE: A multi-stage heat treating method for 2090 aluminum alloy is provided to improve the elongation ratio of aluminum alloy without the deterioration of strength through two-stage and three-stage heat treatments by adding indium without cold working. CONSTITUTION: A multi-stage heat treating method for 2090 aluminum alloy is as follows. 2090 aluminum alloy comprises lithium of 1.9-2.6wt.%, copper of 2.4-3.0wt.%, zirconium of 0.08-0.15wt.%, and aluminum and inevitable impurities of the remaining amount. Indium of 0.04-0.08wt.% is added to the 2090 aluminum alloy to obtain alloy. Two- or three-stage aging and heat treatment of the alloy is implemented after solution-treating.
Abstract:
A method of manufacturing a surface crack-free good steel plate containing Cu through a new hot rolling process of performing rolling of a Cu-containing ingot or slab twice by considering high temperature characteristics of a Cu-containing steel product without using conventional methods of adding alloy elements, using a surface coating agent, and controlling the atmosphere within a furnace is provided. A manufacturing method of a Cu-containing steel plate comprises the steps of: preparing an ingot or a slab made from a Cu-containing alloy steel comprising, by weight percent, 0.02 to 0.5% of C, 0.2 to 1.0% of Mn, 0.5% or less of Si, 0.5 to 4.0% of Ni, 0.3 to 1.2% of Cr, 0.1 to 1.0% of Mo, 0.5 to 2.0% of Cu, 0.01 to 0.08% of Nb, and the balance of Fe and inevitably contained impurities; heating the ingot or slab at a temperature of 1140 to 1250 deg.C, and subjecting the heated ingot or slab to a first hot rolling process such that thickness of the ingot or slab is reduced to 30 to 70% of an initial thickness of the ingot or slab at a finish rolling temperature of 900 to 1100 deg.C; and reheating a hot rolled steel plate of which a production thickness is reduced according to the first hot rolling process at a temperature of 1140 to 1250 deg.C, and performing a second hot rolling process of the reheated hot rolled steel plate to a product thickness at a finish rolling temperature of 800 deg.C or more.
Abstract:
본 발명은 항공기, 미사일, 경량 장갑재 및 각종 군수용품으로 사용되는 2090 알루미늄 합금의 연신율 향상을 위한 열처리 방법에 관한 것이며, 기존 열처리 공정에 의하여 얻어지는 연신율보다 높은 값을 보유할 수 있는 2090 알루미늄 합금의 열처리 방법을 제공한다. 상기 목적 달성을 위한 본 발명에 따른 2090 알루미늄 합금의 열처리 방법은, 2090 알루미늄 합금에 인듐을 0.04∼0.08wt% 첨가하여, 용체화 처리후 2단 시효(160∼190℃, 9∼30시간 + 130℃, 165시간) 또는 3단 시효(160∼190℃, 9∼30시간 + 90∼110℃, 3∼5시간 + 145∼150℃, 30∼48시간)하는 시효 열처리 방법에 관한 것이며, 2단 또는 3단 시효 열처리 후 기존 열처리 방법의 연신율(0.5∼6.5%)에 비해 강도 저하는 없으면서 7.9∼13.1%의 현저히 증가된 연신율을 보여준다.
Abstract:
PURPOSE: W-containing secondary hardening alloy steel with superior intensity and fracture toughness and a manufacturing method thereof are provided to minimize the content of S in alloy steel through ESR(Electro Slag Remelting) after vacuum melting. CONSTITUTION: A method for manufacturing W-containing secondary hardening Co(Cobalt)-Ni(Nickel) alloy steel is as follows. A steel material, which comprises C(Carbon) of 0.23-0.28wt.%, Cr(Chromium) of 2.00-3.50wt.%, W of 0.40-4.05wt.%, Ni of 7.50-11.05wt.%, Co of 11.00-13.50wt.%, and Fe(Iron) and impurities of the remaining amount, is manufactured through a hot forming process using ESR after vacuum induction melting. The steel material is maintained at a temperature of 1000-1200°C for 60-120 minutes and rapidly cooled. The cooled steel material is aged at a temperature of 480-510°C for 60-600 minutes.
Abstract:
PURPOSE: A metal plate forming apparatus using underwater gunpowder explosion, a metal plate forming system with the same, and a metal plate forming method are provided to simply control the thickness strain degree of a metal plate by regulating the amount of gunpowder and the distance between a mold and the metal plate. CONSTITUTION: A metal plate forming system comprises a jig assembly(110), a gunpowder explosion module(120), and a jig assembly setting module(200). The jig assembly includes one or more molds, wherein a metal plate is mounted separate from the forming surface of the molds. The gunpowder explosion module arranges gunpowder(102) at a position separated from the metal plate and explodes the gunpowder from a distance. The jig assembly setting module submerges the jig assembly into the water so that the explosive power of the gunpowder is transmitted to the metal plate under the water and the metal plate is shaped. The space between a forming surface of the jig assembly and the metal plate is sealed up and kept in a vacuum by an exhaust valve of the jig assembly connected to a vacuum pump.