Study on Microstructure and Mechanical Properties of Welding Coarse Grain Heat-Affected Zone of High-Nb X80 Steels

2012 ◽  
Vol 13 (1) ◽  
pp. 780-783 ◽  
Author(s):  
Xiao-Wei Chen ◽  
Gui-Ying Qiao ◽  
Xu Wang ◽  
Fu-Ren Xiao ◽  
Bo Liao
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
Coarse Grain ◽  
Microstructure And Mechanical Properties ◽  
X80 Steels

scholarly journals Microstructure and Mechanical Properties of Heat-Affected Zone of Repeated Welding AISI 304N Austenitic Stainless Steel by Gleeble Simulator

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 773
Author(s):  
Y.H. Guo ◽  
Li Lin ◽  
Donghui Zhang ◽  
Lili Liu ◽  
M.K. Lei
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Energy ◽  
Heat Affected Zone ◽  
Ferrite Content ◽  
Equipment Safety ◽  
Microstructure And Mechanical Properties ◽  
Δ Ferrite ◽  
The Impact

Heat-affected zone (HAZ) of welding joints critical to the equipment safety service are commonly repeatedly welded in industries. Thus, the effects of repeated welding up to six times on the microstructure and mechanical properties of HAZ for AISI 304N austenitic stainless steel specimens were investigated by a Gleeble simulator. The temperature field of HAZ was measured by in situ thermocouples. The as-welded and one to five times repeated welding were assigned as-welded (AW) and repeated welding 1–5 times (RW1–RW5), respectively. The austenitic matrices with the δ-ferrite were observed in all specimens by the metallography. The δ-ferrite content was also determined using magnetic and metallography methods. The δ-ferrite had a lathy structure with a content of 0.69–3.13 vol.%. The austenitic grains were equiaxial with an average size of 41.4–47.3 μm. The ultimate tensile strength (UTS) and yield strength (YS) mainly depended on the δ-ferrite content; otherwise, the impact energy mainly depended on both the austenitic grain size and the δ-ferrite content. The UTS of the RW1–RW3 specimens was above 550 MPa following the American Society of Mechanical Engineers (ASME) standard. The impact energy of all specimens was higher than that in ASME standard at about 56 J. The repeated welding up to three times could still meet the requirements for strength and toughness of welding specifications.

Effects of Welding Wire Composition on Microstructure and Mechanical Properties of Welded Joint in Al-Mg-Si Alloy

2022 ◽  
Vol 905 ◽  
pp. 44-50
Author(s):  
Li Wang ◽  
Ya Ya Zheng ◽  
Shi Hu Hu
Keyword(s):  
Mechanical Properties ◽  
Fusion Zone ◽  
Heat Affected Zone ◽  
Welded Joint ◽  
Weld Zone ◽  
Xrd Analysis ◽  
Metallographic Analysis ◽  
Strengthening Effect ◽  
Welding Wire ◽  
Microstructure And Mechanical Properties

The effects of welding wire composition on microstructure and mechanical properties of welded joint in Al-Mg-Si alloy were studied by electrochemical test, X-ray diffraction (XRD) analysis and metallographic analysis. The results show that the weld zone is composed of coarse columnar dendrites and fine equated grains. Recrystallized grains are observed in the fusion zone, and the microstructure in the heat affected zone is coarsened by welding heat. The hardness curve of welded joint is like W-shaped, the highest hardness point appears near the fusion zone, and the lowest hardness point is in the heat affected zone. The main second phases of welded joints are: matrix α-Al, Mg2Si, AlMnSi, elemental Si and SiO2. The addition of rare earth in welding wire can refine the grain in weld zone obviously, produce fine grain strengthening effect, and improve the electrochemical performance of weld.

Bimodal Microstructure and Mechanical Properties of Cryomilled Nanocrystalline Al-7.5Mg

2002 ◽  
Vol 740 ◽  
Author(s):  
Zonghoon Lee ◽  
David B. Witkin ◽  
Enrique J. Lavernia ◽  
Steven R. Nutt
Keyword(s):  
Mechanical Properties ◽  
Hot Isostatic Pressing ◽  
Tensile Behavior ◽  
Deformation Mechanisms ◽  
Coarse Grained ◽  
Nanocrystalline Powders ◽  
Coarse Grain ◽  
Microstructure And Mechanical Properties ◽  
Bulk Nanocrystalline ◽  
Extensive Plastic Deformation

ABSTRACTThe microstructure and mechanical properties consisting of tensile behavior and hardness of bulk nanocrystalline Al-7.5Mg alloy were investigated. Grain refinement was achieved by cryomilling of atomized Al-7.5Mg powders, and then nanocrystalline powders blended with 15% and 30% coarse-grained Al-7.5Mg powders were consolidated by hot isostatic pressing (HIP) followed by extrusion to produce bulk nanocrystalline Al-7.5Mg alloys. Bimodal structures, which enhance ductility and toughness of nanocrystalline metals, were produced that consisted of nanocrystalline grains and elongated coarse-grain bands. Examination of indentation revealed unusual deformation mechanisms and interactions between the coarse-grain bands and nanocrystalline regions. The ductile coarse-grain bands underwent extensive plastic deformation near indentation, while nanocrystalline regions exhibited limited deformation.

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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