Effect of Welding Heat Circulation on the Microstructure and Mechanical Properties of 500MPa Ultra Fine Grained Steel in HAZ

2011 ◽  
Vol 189-193 ◽  
pp. 3377-3382
Author(s):  
Hong Yun Zhao ◽  
Bo Chen ◽  
Li Zhou ◽  
Guo Dong Wang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Heating Temperature ◽  
Growing Up ◽  
Fine Grained ◽  
Analogue Experiments ◽  
And Performance ◽  
Better Than

Focusing on the need of actual production, physical analogue experiments were done on the 400MPa ultra fine grained steel under different welding heat circulations. The experiment results showed that grains growing up and performance dropping was inevitable, the coarsening temperature range was 1000~1200 ; where the heating temperature was 800 in the Heat Affected Zone, the soften was the most obvious, but when the cooling rate t8/5<10s, the soften disappeared; speeding up the cooling rate could improve the microstructure of the Heat-affected Zone effectively and made the mechanical properties of the joint better than that of the base metal.

Gas metal arc welding of XPF800 steel for automotive industry: Microstructural evaluation and mechanical properties investigation

2021 ◽  
pp. 146442072110567
Author(s):  
Emre Korkmaz ◽  
Cemal Meran
Keyword(s):  
Mechanical Properties ◽  
Base Metal ◽  
Automotive Industry ◽  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Charpy Impact ◽  
Optical Microscope ◽  
Metal Arc Welding ◽  
Heat Affected Zone Softening

In this study, the effect of gas metal arc welding on the mechanical and microstructure properties of hot-rolled XPF800 steel newly produced by TATA Steel has been investigated. This steel finds its role in the automotive industry as chassis and seating applications. The microstructure transformation during gas metal arc welding has been analyzed using scanning electron microscope, optical microscope, and energy dispersive X-ray spectrometry. Tensile, Charpy impact, and microhardness tests have been implemented to determine the mechanical properties of welded samples. Acceptable welded joints have been obtained using heat input in the range of 0.28–0.46 kJ/mm. It has been found that the base metal hardness of the welded sample is 320 HV0.1. On account of the heat-affected zone softening, the intercritical heat-affected zone hardness values have diminished ∼20% compared to base metal.

Study on Characteristics of Outlast Acrylic Fiber

2012 ◽  
Vol 627 ◽  
pp. 85-89 ◽  
Author(s):  
Hai Xia Zhang ◽  
Xi Chang Zhang
Keyword(s):  
Mechanical Properties ◽  
Phase Change ◽  
Physical And Mechanical Properties ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Acrylic Fiber ◽  
Change Temperature ◽  
And Performance ◽  
Cooling Velocity ◽  
Better Than

To analyze the structure and performance of Outlast acrylic fiber, the fiber structure was observed respectively by FTIR spectra, X-ray diffraction and scanning electron microscope, the normal physical and mechanical properties were measured, and the thermo-regulated performance was investigated by differential scanning calorimeter, thermal gravimeter analysis and step cooling test. The results indicate that the structure and normal physical and mechanical properties of Outlast acrylic fiber are slightly different from that of normal acrylic fiber. Both the melting peak and crystallization peak of Outlast acrylic fiber are single peaks, and the phase change temperature range is applicable and the phase change enthalpy is high. The decomposition temperature of Outlast acrylic fiber is around 311.85°C. The cooling velocity of Outlast acrylic fiber decreases exponentially with the increase in time, and the thermo-regulated ability of Outlast acrylic fiber is better than that of normal acrylic fiber.

Mechanical Properties and Fracture Toughness of Aluminum Vessels by Friction Stir Welding

2004 ◽  
Author(s):  
Masahito Mochizuki ◽  
Masao Toyoda ◽  
Masayuki Inuzuka ◽  
Hidehito Nishida
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Crack Initiation ◽  
Base Metal ◽  
Welded Joint ◽  
Stir Zone ◽  
Crack Initiation And Propagation ◽  
Friction Stir ◽  
Fine Grained ◽  
Initiation And Propagation

Mechanical properties and fracture toughness in friction stir welded joint of vessels of structural aluminum alloy type A5083-O are investigated. Welded joint from 25 mm-thick plate is fabricated by one-side one-pass friction stir. Charpy impact energy and critical crack-tip opening displacement (CTOD) in friction stir weld are much higher than those of base metal or heat-affected zone, whereas mechanical properties such as stress-strain curve and Vickers hardness do not have a conspicuous difference. Effects of microstructure on crack initiation and propagation are studied in order to clarify the difference of fracture toughness between stir zone and base metal. Both tensile test and bending test show that the fine-grained microstructure in stir zone induces to increase ductile crack initiation and propagation resistance by analyzing fracture resistance curves and diameter of dimples in fracture surface. It is found that high fracture toughness value in stir zone is affected fine-grained microstructure by friction stirring.

Mechanical Properties and Microstructures of Narrow Gap Orbital Welded P91 Steel

2016 ◽  
Vol 258 ◽  
pp. 635-638 ◽  
Author(s):  
Michal Junek ◽  
Marie Svobodová ◽  
Jiří Janovec ◽  
Jakub Horváth
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Room Temperature ◽  
Tensile Specimen ◽  
Narrow Gap ◽  
P91 Steel ◽  
Microstructure Evaluation ◽  
The Individual

This article deals with the results of mechanical testing and structural analysis of sections of narrow gap orbital welded P91 steel on tube OD 355.6 x 40 mm. The evaluation of mechanical properties was based on tensile test at room temperature on mini-tensile specimens and on measurement of modulus of elasticity. Weld was cut longitudinally into 9 narrow slices by using waterjet. From these slices 108 flat mini-tensile specimens (dimensions of gauge is 2 x 2 mm) were prepared. In experimental part microstructure evaluation and documentation of fracture surface of each mini-tensile specimen were carried out. The aim of these experiments was to assess the mechanical properties of the individual sections of the weld (base metal, heat affected zone and weld metal). These data can be used for new approaches of FEM modelling of welds considering heat affected zone like a combination of different materials with different mechanical properties, which connect the thermally unaffected base metal and weld metal.

scholarly journals MODELING THE WORK OF THE HEAD OF A HYDROMECHANICAL EXPANDER FOR WELDED PIPES OF A LARGE DIAMETER

2020 ◽  
pp. 35-42
Author(s):  
L. M. Gurevich ◽  
V. F. Danenko ◽  
A. A. Istrati ◽  
V. A. Sonnova
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Internal Pressure ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Welded Joint ◽  
Large Diameter ◽  
Design Parameters ◽  
Maximum Stresses ◽  
Distribution Of Stresses

Finite element simulates of changing stresses and strains under loading by gradually increasing internal pressure of cylindrical welded vessels was carried out. The vessels had an annular mechanically inhomogeneous welded joint with different mechanical properties of the joint, heat-affected zone, and base metal. Maximum stresses developed in the caps of the vessels, and the annular joint are lightly loaded. The distribution of stresses and strains in joint at various design parameters of the vessels is investigated.

scholarly journals The Effects of Transition Metal Oxides (Me = Ti, Zr, Nb, and Ta) on the Mechanical Properties and Interfaces of B4C Ceramics Fabricated via Pressureless Sintering

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1253
Author(s):  
Guanqi Liu ◽  
Shixing Chen ◽  
Yanwei Zhao ◽  
Yudong Fu ◽  
Yujin Wang
Keyword(s):  
Mechanical Properties ◽  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Milling Process ◽  
Second Phase ◽  
Pressureless Sintering ◽  
And Performance ◽  
Better Than

There is little available research on how different transition metal oxides influence the behavior of B4C-based ceramics, especially for Ta2O5 and Nb2O5. B4C-MeB2 (Me = Ti, Zr, Nb, and Ta) multiphase ceramic samples were prepared via in situ pressureless sintering at 2250 °C, involving the mixing of B4C and MeOx powders, namely TiO2, ZrO2, Nb2O5, and Ta2O5. The phase constituents, microstructures, and mechanical properties of the samples were tested. The results indicated that different transition metal elements had different effects on the ceramic matrix, as verified through a comparative analysis. Additionally, the doped WC impurity during the ball milling process led to the production of (Me, W)B2 and W2B5, which brought about changes in morphology and performance. In this study, the Ta2O5-added sample exhibited the best performance, with elastic modulus, flexural strength, Vickers hardness, and fracture toughness values of 312.0 GPa, 16.3 GPa, 313.0 MPa, and 6.08 MPa·m1/2, respectively. The comprehensive mechanical properties were better than the reported values when the mass fraction of the second phase was around five percent.

Region-Specified Ratcheting Behavior of API X80 Welded Joint Under Uniaxial Cyclic Loading

2016 ◽  
Author(s):  
Hongsheng Lu ◽  
Yonghe Yang ◽  
Gang Chen ◽  
Xu Chen ◽  
Xin Wang
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Welded Joint ◽  
Pipeline Steel ◽  
Coarse Grained ◽  
Strain Accumulation ◽  
Lower Strength ◽  
Fine Grained ◽  
Ratcheting Strain

Evaluation of mechanical performance of different regions can be difficult by using standard size samples due to the size limitation of weld metal and heat-affected zone (HAZ). At first, the microstructure of different regions was characterized and quantified by Scanning Electron Microscope, which indicate that the pipeline steel is a typical acicular ferrite steel. In this study the deformation behavior of different regions (base metal, weld metal and heat affected zone) in a welded joint of API X80 pipeline steel were studied by conducting uniaxial loading tests on miniature specimens with the cross section of 2×0.5mm and gauge length of 9mm. From the results of uniaxial tension in base metal and weld metal it is shown that the welding is overmatching. Compared to the base metal, the coarse grained HAZ exhibits a lower strength, while the fine grained HAZ exhibits a higher strength. Under near zero-to-tension cyclic stress loading, all regions of the welded joints exhibit progressive accumulation of plastic strain. Under the same stress level, the base metal shows the fastest ratcheting strain accumulation, which is the result of lower strength than other regions. This fact may indicate that the ratcheting behavior of the overall welded joint is highly dependence on that of base metal for the present case. But when under the same normalized stress level (σ = σ/σYS), the fine grained HAZ has the highest ratcheting strain accumulation, while the coarse grained HAZ has the lowest ratcheting strain accumulation, which reveals that the intrinsic resistance to ratcheting is yield strength dependent.

Effect of Cooling Condition on Microstructure and Mechanical Properties in Large Line Energy Welded Joints of Ultra-Fine Grained Steel

2011 ◽  
Vol 189-193 ◽  
pp. 3345-3350 ◽  
Author(s):  
Hong Yun Zhao ◽  
Li Zhou ◽  
Bo Chen ◽  
Guo Dong Wang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Cooling Condition ◽  
Water Cooling ◽  
Line Energy ◽  
Fine Grained ◽  
Heavy Plate ◽  
Microstructure And Mechanical Properties

The medium and heavy plate of 800 MPa grade ultra-fine grained steel was welded by CO2 gas shielded welding using large line energy. The effect of cooling condition on microstructure and mechanical properties of welded joints was investigated. The results showed that the cases about significant grain size increasing and strength decreasing do exist in the heat affected zone of large line energy welded joints of 800 MPa grade ultra-fine grained steel. Grain growth and softening in the heat affected zone could be suppressed effectively by water cooling in the course of welding. The mechanical properties of welded joints could be significantly increased by water cooling, and the process of CO2 gas shielded welding under water cooling is practical for joining ultra-fine grained steel using large line energy.

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