L. Willertz - Academia.edu (original) (raw)
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CSIC (Consejo Superior de Investigaciones Científicas-Spanish National Research Council)
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Papers by L. Willertz
The corrosion fatigue strengths of Type 403 and 17-4 PH stainless steel and several processing va... more The corrosion fatigue strengths of Type 403 and 17-4 PH stainless steel and several processing variations of Ti-6Al-4V were determined in various steam turbine environments. Steam and turbine deposits were analyzed to establish test environments. Pure 80°C water base line data was determined and compared to saturated aqueous solutions of NaCl, NaâSOâ, NaâPOâ, NaâSiOâ and some mixtures of these. The
International Materials Reviews, 1980
The changes in the damping properties of AISI 403 with cyclical torsional fatigue stressing have ... more The changes in the damping properties of AISI 403 with cyclical torsional fatigue stressing have been determined in order to define the cyclical stress sensitivity limit (CSSL) of the material. Comparision of the data with observations of changes in surface features and the torsional and push-pull fatigue lives shows that the CSSL is a good indication of the minimum stress which can cause permanent fatigue damage in this material. The type of test used to determine the CSSL is rapid in that less than one day's testing on one specimen is required to define it, whereas the usual fatigue limit requires testing times of several weeks and a number of different specimens. Application of the Granato-Lucke theory of dislocation damping explains many of the observations of damping and modulus changes encountered.
Scripta Metallurgica, 1979
The objective of this study is to evaluate the use of coatings to protect low-pressure, steam-tur... more The objective of this study is to evaluate the use of coatings to protect low-pressure, steam-turbines from corrosion which will lead to early component failure. Initially a literature search and supplier visits were conducted to select twenty-four promising coating systems. Metal coupons coated with these systems were examined by mechanical and metallographical methods to determine coating effects on the substrate metal and to determine overall coating integrity and characteristics. Similar coated specimens were subjected to salt spray and 20 kHz corrosion-fatique screening tests. The results of these evaluations are presented and will form the basis to select four high-potential coatings for further test evaluation. Duplicate specimens coated with the available twenty-four coating systems were applied on stressed U-bends of two blading alloys and one rotor-and-disc alloy. These specimens were placed in an operating team turbine. Results of these field tests will be reported after ...
Metallurgical Transactions, 1970
The corrosion fatigue strengths of Type 403 and 17-4 PH stainless steel and several processing va... more The corrosion fatigue strengths of Type 403 and 17-4 PH stainless steel and several processing variations of Ti-6Al-4V were determined in various steam turbine environments. Steam and turbine deposits were analyzed to establish test environments. Pure 80°C water base line data was determined and compared to saturated aqueous solutions of NaCl, NaâSOâ, NaâPOâ, NaâSiOâ and some mixtures of these. The
International Materials Reviews, 1980
The changes in the damping properties of AISI 403 with cyclical torsional fatigue stressing have ... more The changes in the damping properties of AISI 403 with cyclical torsional fatigue stressing have been determined in order to define the cyclical stress sensitivity limit (CSSL) of the material. Comparision of the data with observations of changes in surface features and the torsional and push-pull fatigue lives shows that the CSSL is a good indication of the minimum stress which can cause permanent fatigue damage in this material. The type of test used to determine the CSSL is rapid in that less than one day's testing on one specimen is required to define it, whereas the usual fatigue limit requires testing times of several weeks and a number of different specimens. Application of the Granato-Lucke theory of dislocation damping explains many of the observations of damping and modulus changes encountered.
Scripta Metallurgica, 1979
The objective of this study is to evaluate the use of coatings to protect low-pressure, steam-tur... more The objective of this study is to evaluate the use of coatings to protect low-pressure, steam-turbines from corrosion which will lead to early component failure. Initially a literature search and supplier visits were conducted to select twenty-four promising coating systems. Metal coupons coated with these systems were examined by mechanical and metallographical methods to determine coating effects on the substrate metal and to determine overall coating integrity and characteristics. Similar coated specimens were subjected to salt spray and 20 kHz corrosion-fatique screening tests. The results of these evaluations are presented and will form the basis to select four high-potential coatings for further test evaluation. Duplicate specimens coated with the available twenty-four coating systems were applied on stressed U-bends of two blading alloys and one rotor-and-disc alloy. These specimens were placed in an operating team turbine. Results of these field tests will be reported after ...
Metallurgical Transactions, 1970