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Volume 18, Issue 12
Displaying 1-5 of 5 articles from this issue
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Toshiyasu FUKUI, Yoshihiko SUGIYAMA, Shiro TERAI1968 Volume 18 Issue 12 Pages 609-616
Published: December 30, 1968
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSStudies were made on the effects of nitrogen, oxygen, and hydrogen gases added to argon gas on the weldability and properties of MIG welds of aluminum alloys.
Tests were carried out to observe appearance, shape and depth of penetration, mechanical properties, porosities, structures and other properties of welds. The results obtained were as follows;
(1) The addition of nitrogen was considered to be effective in practical application for increasing the depth of penetra tion, tensile strength, and refining of the structure in welds.
In commercially pure aluminum, it decreased the porosities of welds with no formation of scale on bead surface; while, in Al-Mg alloys, it formed the brown scale on bead surface and the porosities were not always decreased.
(2) The addition of oxygen was considered to be adaentageous in practical application, because it increased the depth ofpenetration and decreased the porosities of welds. However, its addition of above 5% was harmful owing to the puckering and formation of excessive oxide film (white scale) on the bead surface.
(3) The addition of hydrogen was harmful, because it remarkably increased the porosities, resulting in decreasing of the mechanical properties of welds.View full abstractDownload PDF (1614K) -
Taiichiro MANTANI, Hideo NOTANI1968 Volume 18 Issue 12 Pages 617-621
Published: December 30, 1968
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSIn the previous paper it was reported that grains in bead of MIG welded aluminum alloys were refined and welding cracks were decreased by the addition of nitrogen to argon gas.
However, the welding usability was lowered by the addition of nitrogen; i.e., the stability of arc was made poor and the appearance of bead was made irregular.
In order to avoid the above defects, He-N2 mixed gas was used for MIG welding of the specimens instead of Ar-N2 mixed gas.
The following results were obtained.
(1) Arc was made more stable and the appearance of bead was also made better in He-N2 than in Ar-N2 gas.
(2) The depth of penetration was increased by the addition of nitrogen.
(3) The grains in bead were refined by MIG welding in He-N2 as well as in Ar-N2 gas, when Al-Zn-Mg alloys containing small amounts of titanium and zirconium (which are powerful elements for grain refining) were used for the parent metal.
(4) Welding cracks were decreased in inert gases containing nitrogen for the welding of Al-Zn-Mg alloys.View full abstractDownload PDF (1115K) -
Taiichiro MANTANI, Hideo NOTANI1968 Volume 18 Issue 12 Pages 622-626
Published: December 30, 1968
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThis paper reports the effects of mixing ratios among argon, helium, and nitrogen on welding usability, grain size of beads, and cracks.
The following results were obtained.
(1) When the mixing ratios of gases in MIG welding were proper, welding usability was as good as that in He-N2 gas.
(2) Generally, mixed gas of helium (30-60%) nitrogen (about 14%), and argon (the balance) was effective for the welding of Al-Zn-Mg alloys and Al-Mg alloys.
(3) The grains in bead of welded specimens containing titanium and zirconium were refined by the addition of nitrogen to the shield gas, the same as the results in the previous report.
(4) Welding cracks were decreased in the specimens, of which the grains in bead had been refined by the addition of nitrogen.View full abstractDownload PDF (863K) -
Seiki NISHI, Takeo SHINODA, Eiji KATO1968 Volume 18 Issue 12 Pages 627-635
Published: December 30, 1968
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe effects of iron contents, beryllium addition, and cooling velocity on the mechanical properties of Al-Si(5%)-Mg(0.5-0.8%)-Zn(2%) alloys were studied and the following results were obtained.
(1) The mechanical properties of these alloys were more deteriorated with the increase of iron content. It was desirable to keep the iron content at lower than 0.15%.
(2) Addition of about 0.1% of Be to these alloys prevented the decrease of tensile strength when their iron contents were hight.
(3) When the cooling velocity was higher in the range of these experiments, tensile strength was not much varied, but elongation was considerably improved.View full abstractDownload PDF (2340K) -
In paticular, with respect to designation, composition and propertiesTakashi OIKAWA1968 Volume 18 Issue 12 Pages 636-654
Published: December 30, 1968
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (2126K)
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