Post-weld Tempered Microstructure and Mechanical Properties of Hybrid Laser-Arc Welded Cast Martensitic Stainless Steel CA6NM

Mirakhorli, Fatemeh; Cao, X.; Pham, Xuan-Tan; Wanjara, P.; Fihey, J. L.

doi:10.1007/s11663-015-0578-5

Cited by 11 publications

(6 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From a perspective of material design allowable data for CA6NM EB welds after PWHT, the global tensile properties measured from samples T3-T4 are representative of the entire welded assembly, due to the sampling of each characteristic region-FZ, HAZ, and BM-in the weldment. Overall, these tensile properties for the PWHTed CA6NM EB welds corroborate well with those reported previously [21,31] for low-carbon 13% Cr-4% Ni martensitic stainless steel grades, including UNS S41500, as tabulated in Table 4.…”

Section: Global and Local Properties From Static Tensile Loading Of Pwhted Ca6nmsupporting

confidence: 90%

“…us, during tensile loading of the PWHTed EB welds, microvoids initiated through decohesion between the martensitic matrix and these particles/inclusions and/or rupture of the particles/inclusions. Overall, the failure mechanisms describing fracture initiation (microvoids), propagation (void coalescence), and rupture (cracking) for the PWHTed CA6NM EB welds are in good agreement with the observations reported for PWHTed CA6NM welds joined by HLAW [31] and PWHTed UNS S41500 EB welds [21].…”

Section: Global and Local Properties From Static Tensile Loading Of Pwhted Ca6nmsupporting

confidence: 86%

See 1 more Smart Citation

Through‐Thickness Residual Stresses, Microstructure, and Mechanical Properties of Electron Beam‐Welded CA6NM Martensitic Stainless Steel after Postweld Heat Treatment

Sarafan

Wanjara

Lévesque

et al. 2020

Advances in Materials Science and Engineering

Self Cite

View full text Add to dashboard Cite

In this study, the integrity of electron beam- (EB-) welded CA6NM—a grade of 13% Cr-4% Ni martensitic stainless steel—was assessed through the entire joint thickness of 90 mm after postweld heat treatment (PWHT). The joints were characterized by examining the microstructure, residual stresses, global mechanical properties (static tensile, Charpy impact, and bend), and local properties (yield strength and strain at fracture) in the metallurgically modified regions of the EB welds. The applied PWHT tempered the “fresh” martensite present in the microstructure after welding, which reduced sufficiently the hardness (<280 HV) and residual stresses (<100 MPa) to meet the requirements for hydroelectric turbine assemblies. Also, the properties of the EB joints after PWHT passed the minimum acceptance criteria specified in ASME sections VIII and IX. Specifically, measurement of the global tensile properties indicated that the tensile strengths of the EB welds in the transverse and longitudinal directions were on the same order as that of the base metal (BM). Evaluation of the local tensile properties using a digital image correlation (DIC) methodology showed higher local yield strengths in the fusion zone (FZ) and heat-affected zone (HAZ) of 727 MPa and 740 MPa, respectively, relative to the BM value of 663 MPa. Also, the average impact energies for the FZ and HAZ were 63 J and 148 J, respectively, and attributed to the different failure mechanisms in the HAZ (dimples) versus the FZ (quasi-cleavage consisting of facets and dimples). This study shows that the application of PWHT plays an important role in improving the weld quality and performance of EB-welded CA6NM and provides the essential data for validating the design and manufacturing process for next-generation hydroelectric turbine products.

show abstract

Section: Global and Local Properties From Static Tensile Loading Of Pwhted Ca6nmsupporting

confidence: 90%

Section: Global and Local Properties From Static Tensile Loading Of Pwhted Ca6nmsupporting

confidence: 86%

Through‐Thickness Residual Stresses, Microstructure, and Mechanical Properties of Electron Beam‐Welded CA6NM Martensitic Stainless Steel after Postweld Heat Treatment

Sarafan

Wanjara

Lévesque

et al. 2020

Advances in Materials Science and Engineering

Self Cite

View full text Add to dashboard Cite

show abstract

“…For microstructural analysis, samples were prepared using standard metallographic procedure: cutting at the center (thermocouple position); grinding, polishing and applying chemical etching. In order to reveal grain boundaries, phases, precipitates and microconstituents, the [13]. The right side shows the experiments regions simulated performed as shown in Table 3 [14] solution Villela (5 ml HCl, 1 g picric acid and 100 ml ethyl alcohol) was used; for revealing delta ferrite phase, an electrolytical etching consisting of NaOH 40% m/v at 5 V for 30-60 s was applied.…”

Section: Methodsmentioning

confidence: 99%

“…Other studies [12][13][14] regarding CA6NM welding and its heat-affected zones have revealed that CA6NM may possess different amounts of carbides, reversed austenite and residual delta ferrite along grain boundaries presented in various morphologies.…”

Section: Introductionmentioning

confidence: 99%

CA6NM stainless steel submitted to different thermal cycles in the Gleeble weld simulator

Lima¹,

Lourenço²,

Nunes³

et al. 2018

J Braz. Soc. Mech. Sci. Eng.

View full text Add to dashboard Cite

Subregions of CA6NM (ASTM 743) heat-affected zones-HAZ, were investigated in a microstructural and mechanical perspective. Those subregions suffer microstructural changes in welded joints, being considered the most critical regions in welded components. As the HAZ subregions possess very small volume, base metal was submitted to a welding simulation in the physical Gleeble simulator, which allows to reproduce the same microstructures found in real welding, allowing characterization of the different subregions in HAZ. Simulated samples were analyzed by optical microscopy (OM), scanning electron microscopy and X-ray diffraction measurements. For mechanical properties, evaluation samples were submitted to impact and hardness measurements. Microstructural and mechanical analysis for the experiments showed that d-ferrite is found in all HAZ subregions, being related to higher microhardness and higher absorbed energy in impact. Higher heat inputs promoted higher hardness levels and higher d-phase amounts.

show abstract

“…There are usually various solidification defects, such as shrinkage and porosity, in 06Cr13Ni4Mo castings [15]. For safety, these defects must first be dug out, and then welding repair is used to fill the cavities left by the digging [12,[16][17][18][19]. After welding repair, to ensure the quality of the welding, nondestructive testing (NDT) is always performed.…”

Section: Introductionmentioning

confidence: 99%

A Novel Reticular Retained Austenite on the Weld Fusion Line of Low Carbon Martensitic Stainless Steel 06Cr13Ni4Mo and the Influence on the Mechanical Properties

Fan

Zhao²,

Zhao

et al. 2022

Metals

View full text Add to dashboard Cite

When performing fluorescent magnetic particle testing in steel welding-repaired zones, as traditional viewpoint usually ascribes magnetic particle indications to discontinuous welding defects such as cracks, incomplete fusion, etc., welding-repaired zones showing indications of these defects are always judged to be unqualified. In this study, a novel reticular phase was identified on the weld fusion line of 06Cr13Ni4Mo. By selected area electron diffraction, it was proved to be an austenite. By roasting test, it was proved to be induced by the thermal effect of welding. Non-ferromagnetic reticular austenite reduces the overall magnetic permeability, leading to the presence of fluorescent magnetic particle indication. Though the mechanical properties of the welding repaired zone are changed by the reticular austenite with the yield strength, tensile strength, and microhardness decreasing to 571 MPa, 752 MPa, and 279, respectively, they still exceed the required values of standard specifications. 06Cr13Ni4Mo welding-repaired zones showing magnetic particle indications induced by reticular austenite are qualified and should be accepted.

show abstract

Post-weld Tempered Microstructure and Mechanical Properties of Hybrid Laser-Arc Welded Cast Martensitic Stainless Steel CA6NM

Cited by 11 publications

References 27 publications

Through‐Thickness Residual Stresses, Microstructure, and Mechanical Properties of Electron Beam‐Welded CA6NM Martensitic Stainless Steel after Postweld Heat Treatment

Through‐Thickness Residual Stresses, Microstructure, and Mechanical Properties of Electron Beam‐Welded CA6NM Martensitic Stainless Steel after Postweld Heat Treatment

CA6NM stainless steel submitted to different thermal cycles in the Gleeble weld simulator

A Novel Reticular Retained Austenite on the Weld Fusion Line of Low Carbon Martensitic Stainless Steel 06Cr13Ni4Mo and the Influence on the Mechanical Properties

Contact Info

Product

Resources

About