Abstract:
PURPOSE: A wear resistant sintered alloy for valve seat is provided which improves wear resistance and formability by containing iron as a principal constituent, carbon, chromium, molybdenum, vanadium, tungsten, silicon, manganese and lead only without cobalt, and a manufacturing method thereof is provided. CONSTITUTION: The method comprises first process of press molding the blended alloy to a surface pressure of 5 to 8 tons/cm¬2 by blending a principal constituent of iron, 0.3 to 0.5 wt.% of carbon, 1.0 to 3.0 wt.% of chromium, 2.0 to 4.0 wt.% of molybdenum, 2.0 to 4.0 wt.% of vanadium, 5.0 to 7.0 wt.% of tungsten, 0.2 to 0.4 wt.% of sulfur, 0.2 to 0.5 wt.% of manganese and 10.0 to 15.0 wt.% of lead; second process of air cooling the sintered alloy after sintering the press molded alloy at a temperature of 1,140 to 1,180 deg.C after finishing the first process; third process of subzero cooling the air cooled sintered alloy to a temperature of -200 to -600 deg.C after finishing the second process; fourth process of impregnating the subzero cooled alloy with lead at a temperature of 450 to 550 deg.C after finishing the third process; and a process of manufacturing the wear resistant sintered alloy for valve seat by passing the lead impregnated alloy through barrel process at a temperature of 450 to 550 deg.C after finishing the fourth process.
Abstract:
PURPOSE: A wear resistant sintered alloy for valve seat is provided which improves wear resistance and formability by containing iron as a principal constituent, carbon, chromium, molybdenum, vanadium, tungsten, silicon, manganese and lead, and a manufacturing method thereof is provided. CONSTITUTION: The method comprises first process of press molding the blended alloy to a surface pressure of 5 to 8 tons/cm¬2 by blending a principal constituent of iron, 1.2 to 1.7 wt.% of carbon, 3.5 to 5.0 wt.% of chromium, 2.0 to 4.0 wt.% of molybdenum, 3.0 to 5.0 wt.% of vanadium, 7.0 to 10.0 wt.% of tungsten, 2.0 to 3.5 wt.% of cobalt, 0.1 to 1.0 wt.% of boron nitride, 0.2 to 0.4 wt.% of sulfur, 0.2 to 0.5 wt.% of manganese and 10.0 to 15.0 wt.% of lead; second process of air cooling the sintered alloy after sintering the press molded alloy at a temperature of 1,140 to 1,180 deg.C after finishing the first process; third process of subzero cooling the air cooled sintered alloy to a temperature of -200 to -600 deg.C after finishing the second process; fourth process of impregnating the subzero cooled alloy with lead at a temperature of 450 to 550 deg.C after finishing the third process; and a process of manufacturing the wear resistant sintered alloy for valve seat by passing the lead impregnated alloy through barrel process at a temperature of 450 to 550 deg.C after finishing the fourth process.
Abstract:
A sintered alloy having an improved wear resistance and a workability for a valve seat. The alloy contains iron as a main component, carbon, silicon, chromium, molybdenum, cobalt, maganese, lead, vanadium, advantageously boron nitride, and tungsten. The strength, wear resistance, and material properties are improved by a sub-zero treatment. Sintered alloy with wear resistance used for a valve seat comprises Fe as a main component, C of 1.2 to 1.7 wt %, Cr of 3.5 to 5.0 wt %, Mo of 2.0 to 4.0 wt %, V of 3.0 to 5.0 wt %, W of 7.0 to 10.0 wt %, Co of 2.0 to 3.5 wt %, boron nitride of 0.1 to 1.0 wt %, S of 0.2 to 0.4 wt %, Mn of 0.2 to 0.5 wt %, advantageously 0.2 to 0.6% Si, and Pb of 10.0 to 15.0 wt %. Sintered alloy for an valve seat is manufactured by a sub-zero treatment so that the amount of metallic particles separated from a base matrix decreases and a size of the separated metallic particle becomes small.
Abstract:
PURPOSE: A wear resistant sintered alloy for valve seat is provided which improves wear resistance and formability by containing iron as a principal constituent, carbon, chromium, molybdenum, vanadium, tungsten, silicon, manganese and lead only without cobalt, and a manufacturing method thereof is provided. CONSTITUTION: The method comprises first process of press molding the blended alloy to a surface pressure of 5 to 8 tons/cm¬2 by blending a principal constituent of iron, 0.3 to 0.5 wt.% of carbon, 1.0 to 3.0 wt.% of chromium, 2.0 to 4.0 wt.% of molybdenum, 2.0 to 4.0 wt.% of vanadium, 5.0 to 7.0 wt.% of tungsten, 0.2 to 0.4 wt.% of sulfur, 0.2 to 0.5 wt.% of manganese and 10.0 to 15.0 wt.% of lead; second process of air cooling the sintered alloy after sintering the press molded alloy at a temperature of 1,140 to 1,180 deg.C after finishing the first process; third process of subzero cooling the air cooled sintered alloy to a temperature of -200 to -600 deg.C after finishing the second process; fourth process of impregnating the subzero cooled alloy with lead at a temperature of 450 to 550 deg.C after finishing the third process; and a process of manufacturing the wear resistant sintered alloy for valve seat by passing the lead impregnated alloy through barrel process at a temperature of 450 to 550 deg.C after finishing the fourth process.
Abstract:
PURPOSE: A wear resistant sintered alloy for valve seat is provided which improves wear resistance by containing iron as a principal constituent, carbon, chromium, molybdenum, vanadium, tungsten, cobalt, silicon and manganese and simultaneously performing copper infiltration and sintering treatment, and a manufacturing method thereof is provided. CONSTITUTION: The method comprises first process of press molding the blended alloy to a surface pressure of 5 to 8 tons/cm¬2 by blending a principal constituent of iron, 0.8 to 1.2 wt.% of carbon, 2.0 to 5.0 wt.% of chromium, 5.0 to 7.0 wt.% of molybdenum, 3.0 to 5.0 wt.% of vanadium, 8.0 to 12.0 wt.% of tungsten, 0.2 to 0.5 wt.% of manganese and 4.0 to 6.0 wt.% of cobalt; second process of air cooling the pure copper infiltrated and sintered alloy after infiltrating 20 to 30 wt.% of pure copper for the weight of the valve seat into the press molded alloy and sintering the pure copper infiltrated alloy at the same time at a temperature of 1,140 to 1,180 deg.C after finishing the first process; third process of rapidly cooling the heat treated alloy after heat treating the copper infiltrated and sintered alloy to a temperature of 1,130 to 1,180 deg.C after finishing the second process; fourth process of annealing the rapidly cooled alloy to a temperature of 600 to 700 deg.C after finishing the third process; and a process of proceeding some processing works on the annealed alloy at an ordinary temperature after finishing the fourth process.
Abstract:
PURPOSE: A wear resistant sintered alloy for valve seat is provided which improves wear resistance by containing iron as a principal constituent, carbon, chromium, molybdenum, vanadium, tungsten, cobalt, silicon and manganese and simultaneously performing copper infiltration and sintering treatment, and a manufacturing method thereof is provided. CONSTITUTION: The method comprises first process of press molding the blended alloy to a surface pressure of 5 to 8 tons/cm¬2 by blending a principal constituent of iron, 0.8 to 1.2 wt.% of carbon, 2.0 to 5.0 wt.% of chromium, 5.0 to 7.0 wt.% of molybdenum, 3.0 to 5.0 wt.% of vanadium, 8.0 to 12.0 wt.% of tungsten, 0.2 to 0.5 wt.% of manganese and 4.0 to 6.0 wt.% of cobalt; second process of air cooling the pure copper infiltrated and sintered alloy after infiltrating 20 to 30 wt.% of pure copper for the weight of the valve seat into the press molded alloy and sintering the pure copper infiltrated alloy at the same time at a temperature of 1,140 to 1,180 deg.C after finishing the first process; third process of rapidly cooling the heat treated alloy after heat treating the copper infiltrated and sintered alloy to a temperature of 1,130 to 1,180 deg.C after finishing the second process; fourth process of annealing the rapidly cooled alloy to a temperature of 600 to 700 deg.C after finishing the third process; and a process of proceeding some processing works on the annealed alloy at an ordinary temperature after finishing the fourth process.
Abstract:
PURPOSE: A wear resistant sintered alloy for valve seat is provided which improves wear resistance compared to existing sintered alloy for valve seat by performing heat treatment after changing composition for the alloy and infiltrating copper into the alloy simultaneously, and a manufacturing method thereof is provided. CONSTITUTION: The method comprises first step of press molding the blended material to a surface pressure of 5 to 8 ton/cm¬2 by blending a principal constituent of iron, 1.1 to 1.6 wt.% of carbon, 3.0 to 5.0 wt.% of chromium, 2.0 to 4.0 wt.% of molybdenum, 3.0 to 5.0 wt.% of vanadium, 6.5 to 9.5 wt.% of tungsten, 2.0 to 3.5 wt.% of cobalt, 0.2 to 0.6 wt.% of silicon, 0.1 to 1.0 wt.% of boron nitride, 0.2 to 0.4 wt.% of sulfur and 0.2 to 0.5 wt.% of manganese; second step of air cooling the sintered material after sintering the press molded material to a temperature of 1,150 to 1,200 deg.C after finishing the first step; third step of infiltrating 12 to 18 wt.% of pure copper into the air cooled material at a temperature of 1,080 to 1,100 deg.C after finishing the second step; fourth step of oil cooling the pure copper infiltrated material after maintaining the pure copper infiltrated material at a temperature of 850 to 880 deg.C for 30 to 50 min after finishing the third step; and fifth step of tempering the oil cooled material to a temperature of 600 to 650 deg.C after finishing the fourth step.
Abstract:
A coating composition for a sliding member is provided to prevent scuffing caused by a continuous load and heat and to significantly reduce friction and wear. A coating composition for a sliding member comprises: at least one resin material selected from polyamideimide(PAI) resins and polyimide(PI) resins; and at least one solid lubricating agent selected from sulfide, fluorine-containing compounds and graphite, wherein the solid lubricating agent is used in an amount of 1-500 parts by weight based on 100 parts by weight of the resin material. Particular examples of the sulfide include molybdenum disulfide or tungsten disulfide.
Abstract:
본 발명은 탄소 0.2∼0.8 중량% 및 구리 1.0∼5.0 중량%을 포함하고 나머지는 철로 구성되는 저합금 철분말과, 탄소 1.0∼1.3 중량%, 크롬 3.5∼4.2 중량%, 몰리브덴 9.0∼10.0 중량%, 바나듐 1.0∼1.4 중량%, 텅스텐 1.2∼1.8 중량%, 코발트 7.8∼8.5 중량% 및 실리콘 0.5 중량% 이하를 함유하고 나머지는 철로 구성되는 고합금 철분말이 1:1로 혼합된 것을 특징으로 하는 피스톤용 다공질 소결재 인서트 조성물과; 상기 다공질 소결재 인서트 조성물을 금형속에 넣고 링형상의 성형체가 되도록 5∼7kgf/㎠으로 압력을 가하되, 성형체의 밀도는 5.5∼6.5 g/cm 3 가 되도록 하고, 상기 링형상의 성형체를 환원분위기의 소결로에서 소결온도 1050∼1250℃로 30∼60분 동안 소결하여, 기공율이 30∼50 부피%인 다공질의 소결재 인서트로 제조되는 것을 특징으로 하는 피스톤용 다공질 소결재 인서트의 제조 방법을 제공하고자 한 것이다.