The microstructure, mechanical, and fatigue behaviours of MAG welded G20Mn5 cast steel

Wu, Shengchuan; Qin, Qian; Branco, R.; Li, C.H.; Williams, Craig J.; Zhang, W.H.

doi:10.1111/ffe.13215

Cited by 6 publications

(5 citation statements)

References 74 publications

(134 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From Figure 11 , it has been observed that the dendritic microstructures are formed having long columnar grains at the interface ( Figure 11 b) and cellular dendrites ( Figure 11 c). The fusion zone microstructure at this section revels formation of secondary dendritic arm, the magnifying image shows the formation of intermetallic phase whose presence is confirmed through the EDS report ( Figure 11 d), the grains are parallel and distributed uniformly with mix coarse and fine columnar dendritic (uniaxial) which might be due to the proper mixing of material at the fusion zone [ 38 , 39 ]. Figure 12 shows the SEM images of the weld cross section, i.e., at the interface and the fusion zone; this shows the microstructure with no directional solidification with columnar and cellular dendritic structure.…”

Section: Resultsmentioning

confidence: 72%

Fiber Laser Welded Cobalt Super Alloy L605: Optimization of Weldability Characteristics

et al. 2022

View full text Add to dashboard Cite

The present study describes the laser welding of Co-based superalloy L605 (52Co-20Cr-10Ni-15W) equivalent to Haynes-25 or Stellite-25. The influence of laser welding process input parameters such as laser beam power and welding speed on mechanical and metallurgical properties of weld joints were investigated. Epitaxial grain growth and dendritic structures were visible in the weld zone. The phase analysis results indicate the formation of hard phases like CrFeNi, CoC, FeNi, and CFe in the weld zone. These hard phases are responsible for the increase in microhardness up to 321 HV0.1 in the weld zone, which is very close to the microhardness of the parent material. From the tensile strength tests, the ductile failure of welded specimens was confirmed due to the presence of dimples, inter-granular cleavage, and micro voids in the fracture zone. The maximum tensile residual stress along the weld line is 450 MPa, whereas the maximum compressive residual stress across the weld line is 500 MPa. On successful application of Response Surface methodology (RSM), laser power of 1448.5 W and welding speed of 600 mm/min i.e., line energy or heat input equal to 144 J/mm, were found to be optimum values for getting sound weld joint properties. The EBSD analysis reveals the elongated grain growth in the weld pool and very narrow grain growth in the heat-affected zone.

show abstract

Section: Resultsmentioning

confidence: 72%

Fiber Laser Welded Cobalt Super Alloy L605: Optimization of Weldability Characteristics

et al. 2022

View full text Add to dashboard Cite

show abstract

“…The global behavior is very close to the one determined by Han [ 20 ] for G20Mn5QT cast steel at R = −1 (green dashed line). However, a significant difference with the curve from Wu’s study [ 21 ] who characterized the material at R = 0.1 (dotted green line). This difference hints at a significant influence of the average stress on the fatigue life.…”

Section: Low Cycle Fatigue Testsmentioning

confidence: 59%

“…To the best of our knowledge, no detailed analyses of the influence of micro-shrinkages without the presence of macro porosities on low cycle fatigue damage of cast steels are available. Nevertheless, Han [ 20 ] highlighted that cracks initiate around those porosities in G20Mn5QT grade during high cycle fatigue (HCF) tests; as well as Wu in a G20Mn5N grade during low cycle fatigue (LCF) tests [ 21 ]. Moreover, Nagel studied the impact of internal and surface porosities inside cast specimens in G20Mn5Q grade during HCF tests [ 22 ].…”

Section: Introductionmentioning

confidence: 99%

Low Cycle Fatigue of G20Mn5 Cast Steel Relation between Microstructure and Fatigue Life

et al. 2022

View full text Add to dashboard Cite

Cast steel is commonly used to produce structural and safety parts. Foundry processes allow producing parts from scrap steel directly to the required dimensions without any forming operation. Cast components may, however, exhibit macro- and micro-shrinkage porosities. The combined effect of macro- and micro-shrinkages on the fatigue behavior of cast steel has been characterized in the literature. Macro-shrinkages may nowadays be eliminated by adequate positioning of risers. However, micro-shrinkages will always be present in cast steel components. Present work addresses the influence of micro-shrinkage porosity on a G20Mn5 cast steel. G20Mn5 (normalized) ingots have been cast under industrial conditions, but ensuring the absence of macro-porosities. Solidification leads to two very different microstructures prior to the normalization treatment: columnar dendrites beneath the surface (Skin) and equiaxed microstructures close to the center (Core). First, metallographic observations of the whole ingot revealed the same grain size in both areas. Fatigue samples were extracted, by differentiating two sampling volumes corresponding to columnar (S) and equiaxed solidification (C), respectively. The distribution of micro-porosities was determined on all samples by Micro-CT-scans. Core samples exhibit micro-porosities with volumes 1.7 larger than Skin samples. Low cycle fatigue tests (3 levels of fixed plastic strain) were run on both sample series (C, S). Results follow a Manson–Coffin law. Core specimens exhibit lower fatigue life than Skin specimens. The differences in fatigue life have been related successfully to the differences in micro-porosities sizes.

show abstract

“…Wu et al [24] in their work. The second approach rests on using just one sample at higher levels of stress.…”

Section: Diameter Ofmentioning

confidence: 93%

“…The first approach requires more samples to be tested at lower stress amplitudes (levels). This approach makes it possible to determine a confidence interval for the resulting S-N curve, and was chosen, e.g., by Wu et al [24] in their work. The second approach rests on using just one sample at higher levels of stress.…”

Section: Diameter Ofmentioning

confidence: 99%

Assessment the Partial Welding Influences on Fatigue Life of S700MC Steel Fillet Welds

Moravec

Sobotka

Nováková

et al. 2021

Metals

View full text Add to dashboard Cite

Fine-grained steels belonging to the HSLA group (High-Strength Low-Alloy steels) of steels are becoming increasingly popular and are used in both statically and dynamically stressed structures. Due to the method of their production, and thus also the method use to obtain the required mechanical properties, it is really necessary to limit the heat input values for these steels during welding. When applying temperature cycles, HSLA steels in highly heated heat-affected zones (HAZ) reveal intensive grain coarsening and also softening behaviour. This subsequently results in changes in both mechanical and brittle-fracture properties, and the fatigue life of welded joints. While grain coarsening and structure softening have a major effect on the change of strength properties and KCV (Charpy V-notch impact toughness) values of statically stressed welded joints, the effect of these changes on the fatigue life of cyclically stressed welded joints has not yet been quantified. The paper is therefore conceived so as to make it possible to assess and determine the percentage impact of individual aspects of the welding process on changes in their fatigue life. To be more specific, the partial effects of angular deformation, changes that occur in the HAZ of weld, and the notch effect due to weld geometry are assessed.

show abstract

The microstructure, mechanical, and fatigue behaviours of MAG welded G20Mn5 cast steel

Cited by 6 publications

References 74 publications

Fiber Laser Welded Cobalt Super Alloy L605: Optimization of Weldability Characteristics

Fiber Laser Welded Cobalt Super Alloy L605: Optimization of Weldability Characteristics

Low Cycle Fatigue of G20Mn5 Cast Steel Relation between Microstructure and Fatigue Life

Assessment the Partial Welding Influences on Fatigue Life of S700MC Steel Fillet Welds

Contact Info

Product

Resources

About