http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
신한철(H. C. Shin) 한국소성가공학회 2012 한국소성가공학회 학술대회 논문집 Vol.2012 No.5
Plain carbon steels are being replaced by heat treatable steels having high formability due to they require high durability. To make high carbon steel which has a high formability, the effect of hot rolled microstructure, cold rolling and spheroidization annealing parameters on formability and microstructure are investigated. Planar anisotropy parameter shows lower value in hot rolled and 151 spheroidization annealed specimens than final cold rolled and recrystallization annealed specimens, because of its weak textures. In order to reduce annealing time and obtain ideal microstructure which has fine distributed carbide in Batch Annealing Furnace(BAF), 2-step annealing using partial austenitization in BAF is examined. The microstructure of 2-step annealing has fine spheroidized carbide, because partial austenitization accelerate carbide segmentation in I annealing step. Therefore, it shows higher formability than existing specimens which made by established method.
신한철(H. C. Shin),박경수(K. S. Park) 한국소성가공학회 2011 한국소성가공학회 학술대회 논문집 Vol.2011 No.5
Substitutions from high alloyed steels to B-added steels are increased rapidly, because the prices of alloying elements are increased. To increase the maximum hardness of B-added steel, 0.5% C containing B-added high carbon steel developed. One of the old problems to manufacturing high carbon steel is control of cooling in Run-Out-Table (ROT) in hot rolling mill. Especially, the shape problems of coil such as collapsed coil or twisted coil are frequent in the B-added high carbon steels because of their relatively higher hardenability than plain high carbon steel and relatively lower strength than high alloyed steels in high temperature. In order to solve this problem in 0.5% C containing B-added steel, a new ROT cooling model is suggested and tested. The basic concept of this new cooling model is using the medium temperature pyrometer and feed-back control mechanism. The shapes of coils tested 0.5%C containing B-added steel are very good without collapse or twist. One of test manufactured coil is cold rolled and annealed in cold rolling mill to make test specimen for automatic transmission parts. The manufacturability in cold rolling mill is also better than that of high alloyed steel. The cold rolled test specimens are formed to test automotive transmission parts and heat treated. The test parts made by 0.5% C containing B-added high carbon steel developed shows same or higher durability than the old one.