• Title/Summary/Keyword: stainless steel(SUS 304)

Search Result 92, Processing Time 0.027 seconds

A Study on Transition From Cycle-dependent to Time-dependent Crack Growth in SUS304 Stainless Steel (SUS304강의 사이클의존형에서 시간의존형균열성장으로의 천이에 관한 연구)

  • 주원식;조석수
    • Journal of Welding and Joining
    • /
    • v.14 no.1
    • /
    • pp.38-46
    • /
    • 1996
  • High temperature low cycle fatigue crack growth behavior is investigated over a range of two temperatures and various frequencies in SUS 304 stainless steel. It is found that low frequency and temperature can enhance time-dependent crack growth. With high temperature, low frequency and long crack length, ${\Delta}J_c/{\Delta}J_ f$, the ratio of creep J integral range to fatigue J integral range is increased and time-dependent crack growth is accelerated. Interaction between ${\Delta}J_f$ and ${\Delta}J_c$ is occured at high frequency and low temparature and ${\Delta}J_c$, creep J integral range is fracture mechanical parameter on transition from cycle-dependent to time dependent crack growth in creep temperature region.

  • PDF

A Study of Ability of a Rectangular Shell Deep Drawing by Finite Element Program

  • Kumjing, Sanya;Somphasong, Papon
    • International Journal of Advanced Culture Technology
    • /
    • v.3 no.1
    • /
    • pp.68-77
    • /
    • 2015
  • This study was the use of the finite element method in the deep drawing process of a rectangular shell cup. The aim was to analyse the equivalent strain in the workpiece and to find out what happened to the disc blank sheet before the forming by stamping. The rectangular shell cup was $24{\times}30{\times}20$ mm. and made of 2mm.thick SUS 403 and SUS 304 stainless steel. There were 3 types of blank sheets: 1) square sheet 2) 45 degree angled edge cutting sheet 3) circular sheet. It was found out that the drawing up with the use of 3 types of blank sheet made of SUS 304 stainless steel had no risk in the workpiece. For the stamping of the rectangular shell that used a square sheet made of SUS 403 stainless steel, it was found out that there was no risk in the work piece, but with the use of 45 degree angled edge cutting sheet or round sheet, the work piece had a risk to be damaged.

Hardness and adhesion of the reactively sputtered Zr-ZrN on the stainless steel(SUS304) and tool steel(SKH9) (스테인레스와 공구강 위에 스퍼터링된 Zr-ZrN 코팅층의 경도 및 밀착성에 대한 연구)

  • 예길촌;신현준;권식철;백원승
    • Journal of the Korean institute of surface engineering
    • /
    • v.26 no.6
    • /
    • pp.316-326
    • /
    • 1993
  • Adhesion and hardeness are the most important properties of a hard coated layer which is applied to wear-resistant devices. Zr/ZrN layer was deposited on tool steel(SKH9) and stainless steel(SUS304) by a re-active D.C. magnetron sputtering technique and their microhardness and adhesion strength were measured for the films processed by changing the partial pressures of $N_2$ gas (4~10$\times$$10^{-4}$mbar) and the substrate bias voltage(0~250V). The adhesion strength was evaluated by acoustic signals through the scratch-test with the incremental applied load. As the partial pressure of $N_2$ gas and the substrate bias voltage were increased, the adhesion strength of tool steel was observed to be stronger than that of the stainless steel. The adhesion strength was generally, observed to decrease with the same tendency regardless of the kinds of substrates. The adhesion strength of tool steel was increased more and more strongly than that of stainless steel as heat-treated temperature was increased. The strength of tool steel was appeared to be high adhesion strength at $400^{\circ}C$. From the failure mode of the film during the scratch adhesion test, the cohesive failure was observed to be obvious and the adhesive failure in a minor portion in the Zr/ZrN doublelayer regardless of the kinds of substrates.

  • PDF

Friction characteristics of SUS 304 and SUS 630 stainless steel in Dry, Grease-, and Oillubricated conditions and wear property in dry condition before and after Ultrasonic Nano-crystal Surface Modification (SUS 304과 SUS 630 소재의 UNSM(초음파나노 표면개질) 처리전후 Dry, Grease윤활, Oil윤활 상태하에서 마찰특성 및 Dry 상태하에서 마모특성)

  • Kim, J.H.;Pyoun, Y.S.;Park, J.H.;Choi, G.S.;Amanov, Auezhan
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2010.05a
    • /
    • pp.521-522
    • /
    • 2010
  • PDF

A study on electrochemical protection diagrams of steel in nitric and sulfuric acid solutions (질산과 황산 용액중의 철강의 전기방식도에 관한 연구)

  • 전대희;김진경
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.13 no.2
    • /
    • pp.43-63
    • /
    • 1989
  • Various kinds of corrosion prevention methods have been developed. It is known that the method of electrochemical protection is more effective and economical than any other method on the large scale metal structures in corrosive solutions. Strong acid solutions such as nitric and sulfuric acid solutions are often used in industries, and the expensive stainless steel is almost exclusively used for the equipment that comes in contact with such acid solutions. However, it is more reasonable that carbon steel is used rather than stainless steel depending upon concentration of those acid solutions from the economical viewpoint. In this study, the typical strong acid solution such as nitric and sulfuric acid solutions are chosen for the experiment and the selected materials of specimen are the stainless steels of SUS 304L and SUS 316L, the carbon steels of SS 41, SM 50 and RA 32, and highly pure lead. Electrochemical protection diagrams can be drawn with data from the external cathodic and anodic polarization curves of SUS 304L, SUS 316L and SM 50 steels in 5-60% nitric acid solutions and from those polarization curves of SS 41, RA 32, SM 50 and SUS 316L steels, and highly pure lead in 2.5-98% sulfuric acid solutions at the slow scanning rate. The data obtained with using the determination method of the optimum cathodic protection potential, the Tafel extrapolation method and the characteristics of anodic polarization curves. The main results obtained from the diagrams are as follows: 1) In nitric acid solution : (1) Corrosion potentials exist in each of those corrosion zones on the stainless steels in the lower concentration than about 12% solutions and on the high tensile strength steels in the lower concentration than about 30% solutions, but the corrosion current (density) in each zone is small on the above mentioned former steels and large on the latter ones. (2) The stainless steels can be self-passivated in the higher concentration than 15% solutions, and the high tensile strength steels gives rise to the same phenomenon in the higher concentration than 35% solutions. (3) The stainless steels in the lower concentration than 60% solutions and the high tensile strength steels in the higher concentration than 35% solutions can be used without protection, but the latter steels must ve protected anodically in the lower conccentration than about 30% solutions. 2) In sufuric acid solution : (1) The carbon steels can be self-passivated in the higher concentration than 45% solutions, and the SUS 316L steel in higher concentration than 75% solutions and the lead in all concentration solutions also gives rise to the same phenomenon. (2) The lead in the lower concentration than 80% solutions and the SUS 316L steel in the higher concentration than 80% solutions can be used without protection. (3) The carbon steels in the higher concentration than 50% solutions also can be used without protecting economically, but the SUS 316L steel in the 20-70% solutions are considerably corrosive without protecting anodically.

  • PDF

On the Effect of Residual Stress on Fracture Behavior at the Welded Zone According to Annealing Temperature (용접부의 열처리에 따른 잔류응력의 파양거동에 미치는 영향)

  • 정석주
    • Journal of the Korean Society of Safety
    • /
    • v.2 no.3
    • /
    • pp.5-11
    • /
    • 1987
  • In this study, a mild steel (SS41) of the carbon steel, a spring steel (SUP-9), and stainless steel (SUS 304) of the special gceel, etc, are adopted as the experimental materrials and are weded by $CO_2$(SS41, SUP-9), TIG (SUS304), respectively. And the residual stress distribution and fracture behavior at the welded zone are examined according to annealing temperatures of four section involving as welded. As a consequence, the best annealing temperatures that the residual stress is removed enough and mechanical properties are very suitable are at 90$0^{\circ}C$ (SS41), 75$0^{\circ}C$ (SUP-9), 110$0^{\circ}C$ (SUS 304), respectively.

  • PDF

Dynamic tensile characteristics of SUS304L steel sheets (SUS304계열 강판의 동적인장특성)

  • Kim, J.S.;Huh, H.;Lee, J.W.;Kwon, T.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2007.10a
    • /
    • pp.360-363
    • /
    • 2007
  • This paper deals with the dynamic tensile characteristics of the steel sheets for structural members of a train. Train accidents occurs rarely but lead to many casualties and economical loss. Therefore the safety of the train becomes important during the train crash. The dynamic tensile characteristics of the steel sheets are indispensable to analyze the structural crashworthiness. Current research reports the stress-strain curves, fracture elongation and strain rate sensitivities evaluated at the various strain rates especially for SUS304L-ST and SUS304L-LT steel sheets. The results include the difference in the dynamic tensile characteristics of both rolling and transverse directions. Dynamic tensile tests were performed at the strain rates ranging from 0.003/sec to 200/sec using High Speed Material Testing Machine. The materials tested in this research shows interesting behavior at the low strain rates. The strain hardening exponent decreases remarkably while the yield strength increases.

  • PDF

Spalling of the Oxide Scales Foemed on Stainless Steels During Cooling

  • Saeki, Isao;Ogama, Tetsuro;Furuichi, Ryusaburo;Kikkawa, Shinichi
    • Corrosion Science and Technology
    • /
    • v.2 no.5
    • /
    • pp.225-232
    • /
    • 2003
  • High temperature oxidation of SUS430 and SUS304 stainless steels in 16.7 kPa $O_2$ - 20.3 kPa $H_2O$ - balanced N2 atmosphere at 1273 K was studied focused on the scale spalling during cooling after an isothermal oxidation. Spalling of the oxide scale during cooling occurred only for SUS304 stainless steel. The oxide scale was composed of two layers and they detached at the interface between them. The reason for the spalling could not be explained only by thermal stresses applied to the specimen during heating and cooling. A new mechanism for scale spalling was proposed based on combination of thermal stresses and thermal shock caused by a fast Martensite transformation of substrate metal.

An Experimental Study on the Fracture Behavior for Flash Butt Welding Zone (Flash Butt 용접부의 파괴거동에 관한 실험적 연구(I))

  • 김용수;신근하;강동명
    • Journal of the Korean Society of Safety
    • /
    • v.7 no.1
    • /
    • pp.65-72
    • /
    • 1992
  • Objective of this research is to evaluate fracture behaviors of fresh-butt welded metal by the acoustic emission technique. The specimens used are medium carbon steel(SM45C), mild steel (SS41) and stainless steel(SUS304), which have different weldability. The similar welding and dissimilar welding processes are considered, in the former SM45C, SS41 and SUS304 are used, in the later the following metals are used SM45C and SS41, SM45C and SUS304 and SS41 and SUS304. The characteristics of fracture in weld metal are eshmated by the tension test with nominal speciemns, the fracture toughness test with compact tension specimens and fractography analysis. The results of tension test show for base metals and similar welding materials that the yield strength and ultimate strength of similar welding materials are increased, the elongation of those are decreased. The weldability of SUS304 is better than that of SM45C and SS41 In similar welding materials. Mechanical properties of dissimilar welding mateiiths we lower than those of similar welding materials. In dissimilar welding materials, the weldability of SM45C and SUS304 is better than that of SM45C and SS41, and also weidability of SS41 and SUS304 is better than SS41 and SM45C. Comparing mechanical properties with AE counts, it is found that AE conuts appeared on a small before the limit load of elasticity(P$_{e}$), and apper greatly near yield strength region in tension test. These results could contribute to the safety analyses and the evaluation of strength for welding structure.e.

  • PDF

A Study on Surface Properties in SUS 300 base Stainless Steel (SUS 300계 스테인리스강의 표면특성에 관한 연구)

  • Lee, K.K.;Yoon, D.J.;Ghi, W.B.;Choi, D.C.;Lee, D.J.
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.12 no.1
    • /
    • pp.31-39
    • /
    • 1999
  • In the present study, oxidation behavior of 304 and 316 stainless steels was investigated. After solution treatment, specimens were polished up to $1{\mu}m$ $Al_2O_3$ grade and then subjected to oxidation treatment in dry air. The range of temperature was used for oxidation treatment at $300^{\circ}C{\sim}500^{\circ}C$ and TEM was used for analyzing the components and structure of oxide film. Also, these results were compared with the results of ESCA and TG. According to the results of TEM analysis, it was found that Cr oxide film was formed on top of the surface after room temperature oxidation but amorphous Fe oxide was formed on top of the surface and polycrystalline $(Cr,Fe)_2O_3$ was formed below the amorphous Fe oxide layer after $500^{\circ}C$ oxidation treatment. The oxidized specimens at $500^{\circ}C$ showed that 316 stainless steel resists more strongly to grain and grain boundary oxidation than 304 stainless steel. These results suggested that Mo component resolved in 316 stainless steel matrix suppressed the formation of Cr carbide which may results in local Cr deplete area.

  • PDF