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Volume 26 (1988)
- Issue 6 Pages 347-
- Issue 5 Pages 289-
- Issue 4 Pages 165-
- Issue 3 Pages 111-
- Issue 2 Pages 61-
- Issue 1 Pages 3-
Predecessor
Volume 26, Issue 5
Displaying 1-6 of 6 articles from this issue
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Kiyoshi ANDO1988 Volume 26 Issue 5 Pages 289-299
Published: September 25, 1988
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSHigher levels of safety are recently required of such structures as nuclear power plant components, aircrafts, liquified natural gas carrier, etc., with an emphasis on the “leak-before-break” philosophy. The ASME Boiler and Pressure Vessel Code was the first case to incorporate this concept in the form of rule in its Section XI. In terms of rule requirements, however, there still remains much to be addressed and explored.
This paper discusses the evaluation technique for parallel surface crack propagation and coalescence proposed by the DBA-84 committee in HPI.
The validity of this technique was verified by applying it to experimental test data obtained by the AFC Sub-committee in JWES.
For comparison, the ASME Code was applied to the same problem. In addition, the detailed simulation analysis for parallel surface crack propagation was made by modeling the mutual interaction effect of parallel surface cracks at the plate surface as that of parallel through cracks.View full abstractDownload PDF (2610K) -
2nd Report LBB Condition and Crack Opening DisplacementKi Woo NAM, Yuzuru SAKAI, Kotoji ANDO, Nobukazu OGURA1988 Volume 26 Issue 5 Pages 300-309
Published: September 25, 1988
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSThe LBB behavior of a structural component under high stress, low cycle fatigue conditions are an important problem in a nuclear power plants, LNG tankers or chemical plants. This paper is an experimental study to clarify the crack shape at penetration, crack opening behavior after penetration and the LBB conditions on plate specimens (HT80, STS42) and pipe specimens (STS38). The load pFLBB. which realizes the LBB condition is derived based on net stress criterion.
It is found that pFLBB is dependent only on the initial crack length a0. Further more, it is shown that the crack opening displacement V at the center of a penetrated crack is introduced using the gross stress, δG, and the front surface crack length, as, and back surface crack length, ab.View full abstractDownload PDF (2459K) -
Shukuji ASAKURA, Isao MAKATSUGAWA, Yoichi UEHARA1988 Volume 26 Issue 5 Pages 310-316
Published: September 25, 1988
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSThe evaluation of corrosion rate of iron in alkaline solutions with and without chloride ions by means of polarization resistance method was examined. When the iron was not passive, the polarization conductance obtained by imposing square wave current was linearly related to corrosion rate regardless of corrosion forms. The constant correlating between polarization conductance and corrosion rate was discussed. The validity of polarization resistance method with iron in alkaline solutions was proved.View full abstractDownload PDF (742K) -
Evaluation of Hydrogen Embrittlement in Pressure Vessel SteelsJun'ichi KOBAYASHI, Yasuhira TAKESHI1988 Volume 26 Issue 5 Pages 318-323
Published: September 25, 1988
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSAs for steels for pressure vessel used in hydrogen environment, hydrogen embrittlement is one of the most important problem for the integrity of the vessel. The threshold stress intensity (KIH) is considered as one of the most reliable parameter to evaluate the susceptibility of steel to hydrogen embrittlement. Then, the test for KIH measurement was carried out using WOL specimens with different specimen thicknesses immersed in H2S saturated 0.5 percent acetic acid solution at 25°C. The materials used were 80kgf/mm2 class strength quenched and tempered steel with the thickness of 127mm.
The results obtained are as follows;
1) KIH value decreased with decreasing specimen thickness and increasing the ratio of the specimen surface area to the volume of test solution (specific volume of solution).
2) Time dependence of hydrogen absorption in aqueous solution of H2S varied with specimen thickness and specific volume of solution. This phenomena was able to be explained analytically by a hydrogen diffusion model which has boundary conditions that the hydrogen concentration at surface of steels depends on the corrosion rate.
3) A single relationship between KIH value and hydrogen concentration calculated by the hydrogen diffusion model was obtained. In this relationship there is neither thickness effect nor specific volume of solution effect. This relationship should be the inherent hydrogen embrittlement characteristics of the steel.View full abstractDownload PDF (583K) -
Sadao FUKUSHIMA, Takayoshi KASUGAI, John T. BOWKER1988 Volume 26 Issue 5 Pages 324-333
Published: September 25, 1988
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSThe HAZ toughness of three steels all meeting EH36 grade specifications have been investigated. The simulated and real weld HAZ microstructure, notch toughness and CTOD toughness were studied for weld heat inputs of 3.5MJ/m, 6MJ/m and 10MJ/m.
At 3.5MJ/m, Charpy absorbed energy curves for simulated HAZ specimens of three steels were very similar. With the increase in weld heat input, the energy transition curves for steel E, EH36, shifted to a higher temperature compared to those for steels A and C, both EH36 Mod.. Charpy absorbed energy curves for real weld specimens shifted to a lower temperature compared to those for the simulated ones. This tendency was caused by the difference in microstructural constituent and grain size along the fracture path in both specimens.
The CTOD toughness of real weld HAZ's of steels A and C was similar to that of simulated HAZ's. Through the whole weld heat input, the real weld HAZ of steel E showed good toughness in spite of low CTOD values obtained from the simulated HAZ specimens. This resulted mainly from the difference in grain growth and microstructure at the middle of fatigue crack front of both specimens.View full abstractDownload PDF (8847K) -
Teruyoshi UDOGUCHI1988 Volume 26 Issue 5 Pages 334-342
Published: September 25, 1988
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSA brief review and interpretation on the Guideline for Seismic Design of Oil Storage Steel Tanks which is included as a Reference in JIS B 8501-1985 “Welded Steel Tanks for Oil Storage” are described here. The guideline consists mainly of seismic response of oil storage tanks in high and low frequency earthquakes, and evaluations of safety against stress intensities, buckling and elephant foot bulge of shells, and bending of annular plates due to seismic loads. The guideline is related closely to the safety act on oil storage tanks, and some cosiderations on their relations are described.View full abstractDownload PDF (1123K)
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