Oxide Formation during Transpassive Material Removal of Martensitic 42CrMo4 Steel by Electrochemical Machining

Zander, Daniela; Schupp, Alexander; Beyss, Oliver; Rommes, Bob; Klink, Andreas

doi:10.3390/ma14020402

Cited by 14 publications

(17 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, almost no metallic chromium was detected on the surface but about 20% Cr (VI) and 80% Cr (III) after the ECM-B process. These results for ferritic–pearlitic 42CrMo4 steel are almost identical to those for martensitic 42CrMo4 [ 21 ]. Only an increased content of metallic chromium in FP ECM-A compared to QT ECM-A is notable.…”

Section: Resultssupporting

confidence: 70%

“…Comparing ground ferritic–pearlitic with martensitic [ 21 ] 42CrMo4 no changes of the proportion of metallic Fe, Fe (II) and Fe (III) were observed ( Figure 7 a), whereas significant differences in the proportions of Fe (II) and Fe (III) occurred for the different microstructures after ECM-A. A ratio of Fe (III)/Fe (II) = 1/2 was determined for ferritic–pearlitic 42CrMo4.…”

Section: Resultsmentioning

confidence: 99%

“… ICP-MS analysis of the process electrolyte after ECM-A and ECM-B for ferritic–pearlitic (FP) and martensitic (QT) [ 21 ] 42CrMo4. …”

Section: Figurementioning

confidence: 99%

“… Proportion of oxidation states of iron for ( a ) ferritic–pearlitic and martensitic [ 21 ] 42CrMo4 and XPS spectra of the Fe2p3/2 region for ( b ) ground, ( c ) ECM-A and ( d ) ECM-B ferritic–pearlitic 42CrMo4 steel fitted according to [ 28 , 29 ]. …”

Section: Figurementioning

confidence: 99%

“…However, Zander et al [ 21 ] were able to demonstrate an influence of the current density on the composition of the ECM oxide layer for martensitic 42CrMo4. An increase in oxidation number of iron with increasing current density from predominantly Fe II to Fe III was observed by X-ray photoelectron spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Insights on the Influence of Surface Chemistry and Rim Zone Microstructure of 42CrMo4 on the Efficiency of ECM

et al. 2021

Self Cite

View full text Add to dashboard Cite

The electrochemical machining (ECM) of 42CrMo4 steel in sodium nitrate solution is mechanistically characterized by transpassive material dissolution and the formation of a Fe3−xO4 mixed oxide at the surface. It is assumed that the efficiency of material removal during ECM depends on the structure and composition of this oxide layer as well as on the microstructure of the material. Therefore, 42CrMo4 in different microstructures (ferritic–pearlitic and martensitic) was subjected to two ECM processes with current densities of about 20 A/cm2 and 34 A/cm2, respectively. The composition of the process electrolyte was analyzed via mass spectrometry with inductively coupled plasma in order to obtain information on the efficiency of material removal and the reaction mechanisms. This was followed by an X-ray photoelectron spectroscopy analysis to detect the chemical composition and the binding states of chemical elements in the oxide formed during ECM. In summary, it has been demonstrated that the efficiency of material removal in both ECM processes is about 5–10% higher for martensitic 42CrMo4 than for ferritic–pearlitic 42CrMo4. This is on one hand attributed to the presence of the cementite phase at ferritic–pearlitic 42CrMo4, which promotes oxygen evolution and therefore has a negative effect on the material removal efficiency. On the other hand, it is assumed that an increasing proportion of Fe2O3 in the mixed oxide leads to an increase in the process efficiency.

show abstract

Section: Resultssupporting

confidence: 70%

Section: Resultsmentioning

confidence: 99%

“… ICP-MS analysis of the process electrolyte after ECM-A and ECM-B for ferritic–pearlitic (FP) and martensitic (QT) [ 21 ] 42CrMo4. …”

Section: Figurementioning

confidence: 99%

Section: Figurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Insights on the Influence of Surface Chemistry and Rim Zone Microstructure of 42CrMo4 on the Efficiency of ECM

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

Microstructural and chemical surface and rim zone changes of ferrite‐perlite 42CrMo4 steel after electrochemical machining

Ehle

Harst

Meyer

et al. 2021

Materialwissenschaft Werkst

View full text Add to dashboard Cite

Electrochemical machining is based on the anodic dissolution of most metals and generates high quality polished surfaces. However, ferrite‐perlite 42CrMo4 steel reveals local optical changes at the surface after electrochemical finishing, such as a widely variable surface finish from shiny (reflective) to rough (dark) surfaces even after one processing step. The optical different surface areas of ferrite‐perlite 42CrMo4 steel (AISI 4140) are studied by different electron microscopy techniques, x‐ray diffraction and x‐ray photoelectron spectroscopy to gain information about the local chemistry of the reaction layers and residual stresses of the rim zone. The results show that the rim zone for the different surface areas are about 50 nm–100 nm thick and contain oxygen. Selected area diffraction reveals the formation of iron(II/III) oxide (Fe3O4) and x‐ray photoelectron spectroscopy confirms the formation of a mixed iron oxide (Fe3‐xO4) with a variation of the oxidation state for both near‐surface rim zones. Furthermore, the reflective surfaces reveal a homogeneous dissolution of ferrite and cementite lamellae whereas the rough surfaces show a preferred dissolution of cementite and an inhomogeneous dissolution of ferrite within the rim zone. X‐ray diffraction measurements do not show any introduced residual stresses in the rim zone.

show abstract

A novel numerical strategy for modeling the moving boundary value problem of electrochemical machining

Velden

Ritzert

Reese

et al. 2023

Numerical Meth Engineering

View full text Add to dashboard Cite

This work presents a new numerical approach to efficiently model the cathode's moving surface in the moving boundary value problem of electrochemical machining. Until recently, the process simulation with finite elements had the drawback of remeshing required by the changing surface geometries. This disadvantage was overcome by an innovative model formulation for the anodic dissolution that utilizes effective material parameters as well as the dissolution level as an internal variable and, thereby, does not require remeshing. Now, we suggest a new numerical method to model arbitrarily shaped and moving cathodes. Two methodologies are investigated to describe the time varying position of the cathode and compared in terms of implementational effort and numerical efficiency. In the first approach, we change the electric conductivity of elements within the cathode and, in a second approach, we apply Dirichlet boundary conditions on the nodes of corresponding elements. For both methods, elements on the cathode's surface are treated with effective material parameters. This procedure allows for the efficient simulation of industrially relevant, complex geometries without mesh adaptation. The model's performance is validated by means of analytical, numerical and experimental results from the literature. The short computation times make the approach interesting for industrial applications.

show abstract

Oxide Formation during Transpassive Material Removal of Martensitic 42CrMo4 Steel by Electrochemical Machining

Cited by 14 publications

References 40 publications

Insights on the Influence of Surface Chemistry and Rim Zone Microstructure of 42CrMo4 on the Efficiency of ECM

Insights on the Influence of Surface Chemistry and Rim Zone Microstructure of 42CrMo4 on the Efficiency of ECM

Microstructural and chemical surface and rim zone changes of ferrite‐perlite 42CrMo4 steel after electrochemical machining

A novel numerical strategy for modeling the moving boundary value problem of electrochemical machining

Contact Info

Product

Resources

About