scholarly journals Application of hummer peening on base metal to high-strength steel

2018 ◽  
Vol 36 (3) ◽  
pp. 206-211
Author(s):  
Yoshihiro SAKINO ◽  
Yasuyuki KURIHARA ◽  
Seiichiro TSUTSUMI
Keyword(s):  
Base Metal ◽  
High Strength Steel ◽  
High Strength

Welding of Fe-Al Intermetallic Compound and Steel by SPS Technology

2012 ◽  
Vol 581-582 ◽  
pp. 582-585
Author(s):  
Guo Dong Zhang ◽  
Ya Dong Xiao ◽  
Nian Liu ◽  
Min Hong
Keyword(s):  
Intermetallic Compound ◽  
Base Metal ◽  
Heat Affected Zone ◽  
High Strength Steel ◽  
Chemical Potential ◽  
High Strength ◽  
Micro Hardness ◽  
Axial Pressure ◽  
Welding Joint ◽  
Short Period

The welding between Fe-Al intermetallic compound and high-strength steel was done via SPS technology. Microstructure, elements concentration and micro-hardness of welding joint were examined. The results indicated that there was no obvious welding heat-affected zone in both Fe-Al intermetallic compound and high-strength steel. The HAZ microstructures of high-strength steel were mainly martensite. In Fe-Al intermetallic compound, the grain size of heat-affected zone was larger than that of base metal and the density of heat-affected zone was lower than that of base metal. Besides, the grains of base metal had deformation phenomena. The welding joint had steady performance and the connection was reliable. Under the influence of chemical potential differences, unidirectional impulses discharge current and axial pressure, elements diffused perfectly in a short period of time.

Fracture of Surface-Cracked Undermatched Weld Joint in High-Strength Steel

1993 ◽  
Vol 115 (4) ◽  
pp. 229-236 ◽  
Author(s):  
B. Petrovski ◽  
M. Kocak
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Weld Joint ◽  
High Strength Steel ◽  
High Strength ◽  
Applied Strain ◽  
Assessment Procedure ◽  
Strain Accumulation ◽  
Strain Concentration ◽  
Fracture Performance

The objective of this paper is to study the combined effects of weld metal undermatching and crack location on the fracture behavior of transversely loaded butt-welded joints in high-strength steel. Surface-cracked tensile panels were instrumented with stain gages and tested with notch locations at the heat-affected zone (HAZ), base and 30 percent undermatched weld metals. It can be expected that for a given applied strain, the level of the strain concentration developed in undermatched weld region will be significantly lower in the high strain-hardening welds compared to the low work-hardening weld joint in high-strength steels. Therefore, in higher strength steel undermatched welds, substantial increase of the strain accumulation should be expected. Detailed strain measurements and tensile panel tests of this study reveal that if there is a defect in the undermatched weld, a combination of the low weld metal toughness and resulting strain accumulation in the weld metal lead to poor fracture performance. The HAZ notched tensile panel results indicate that weld metal undermatching causes an unsymmetrical strain distribution at the crack vicinity. Despite the occurrence of the high applied strain concentration at the weld metal side of HAZ notched panel, the gross section yielding (GSY) occurred similar to the base metal notched one. On the other hand, weld metal notched panels showed net section yielding (NSY) with a considerably reduced ductility. An important difference in 30 percent undermatched weld joint fracture performance, however, emerges when results are analyzed in terms of crack growth resistance curves. The J R-curves of the HAZ and weld metal notched panels have shown lower resistance behavior compared to the base metal panel. Therefore, it is concluded that the fracture performance of the undermatched welds cannot be fully understood if only strength or total strain capacity (applied side) of the entire panel is considered. The fracture toughness (material resistance side) of the undermatched weld joint should also be an integral part of the fracture performance assessment procedure.

scholarly journals Investigation on Residual Compressive Distribution of High-Strength Steel for Bridges by Base Metal Hammer Impact Peening

2021 ◽  
Vol 2 (4) ◽  
pp. 932-941
Author(s):  
Yasuyuki Kurihara ◽  
Yoshihiro Sakino ◽  
Tomoharu Kato
Keyword(s):  
Residual Stress ◽  
Fatigue Strength ◽  
Base Metal ◽  
High Strength Steel ◽  
Plate Thickness ◽  
Base Material ◽  
Steel Structures ◽  
High Strength ◽  
Hammer Impact ◽  
Ordinary Steel

Various peening techniques have been used to improve the fatigue strength of steel structures. Among them, base metal impact hammer peening shows significant improvement in fatigue strength in ordinary steel, but the effect on high-strength steel has not been sufficiently studied. Accordingly, this study applied base material hammer impact peening to test specimens of 780 MPa grade high-strength steel (HT780) and 490 MPa grade ordinary steel (SM490), and the residual stress was measured and simulated. The experimental results clarified that a large compressive residual stress was introduced into the inner part of the plate thickness near the indentation in the high-strength steel, although the range of introduction of residual stress was equivalent in both the ordinary steel and high-strength steel.

Experiment Research on Tensile-Shear Behavior of Spot-Welded Lap Joints of Ultra-High Strength Steel with Common Steel

2013 ◽  
Vol 716 ◽  
pp. 266-270
Author(s):  
Xiang Li ◽  
Xiao Yang Li ◽  
Hui Ping Yu ◽  
Ya Li
Keyword(s):  
Base Metal ◽  
Heat Affected Zone ◽  
High Strength Steel ◽  
Spot Welding ◽  
Tensile Strain ◽  
High Strength ◽  
Weld Nugget ◽  
Tensile Shear ◽  
Welding Joint ◽  
Ultra High Strength Steel

The welding spot of Ultra-high strength steel of 22MnB5 and common steel of St16 were the investigative objects, the intermediate frequency inverter & electric servo welding system was used to weld the sheets. Electrical measuring test method was used on spot-welded joint under tensile-shear load to determinate the strain of different positions, including the strain of weld nugget, the stain around the nugget and the base metals strain near the weld nugget. The deformation regularity of spot welding joints surrounding and base metal were analysed according to the data. The test provided a reference for the numerical simulation of spot welding model. Test results show that the strain distribution on spot welding joint is not uniform, the strain of the weld nugget center is relatively small, large deformation exists mainly in the heat affected zone. That is to say, the area near the spot-welding joint heat affected zone is prone to yield. The base metal area near the weld nugget is mainly affected by tensile strain, and the strain increases with the increasing of the load. The force condition of the specimen is complicated around the nugget, the relationship between the load and the strain is erratic. The strain of the weld nugget will gradually change from axial compressive strain to axial tensile strain. The strain of spot welding specimen made of dissimilar materials (22MnB5& ST16) is negative, and almost linearly.

COMPARATIVE CHARACTERISTICS OF PHYSICAL AND MECHANICAL PROPERTIES OF COMPOSITE MATERIALS AND HIGH-STRENGTH STEEL 30FGSN2A

2020 ◽  
Author(s):  
I.R. Antypes ◽  
◽  
V.V. Zaitsev ◽  
Keyword(s):  
Composite Materials ◽  
High Strength Steel ◽  
Critical Stress ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Aviation Industry ◽  
Specific Strength ◽  
Aircraft Landing ◽  
Carbon Plastics ◽  
Aircraft Landing Gear

Currently, the use of composite materials is increasingly used in various areas of the national economy, including the aviation industry. The materials of this article are devoted to the study of the use of composite materials for the manufacture of aircraft landing gear in comparison with the traditionally used brand of steel. As a result of the work carried out, it was found that the slope made of carbon fiber showed a critical stress twice as high as its design made of 30xgsn2a steel. In addition, carbon plastics are superior to high-strength steel in terms of specific strength, stiffness, and tensile strength.

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