English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

ZAMPIERI, C. R. J. Determination of fracture toughness in welds in a ferritic ASTM A 335 Gr.P22 steel pipe by Crack Tip Open Displacement (CTOD) method. 92p. Dissertação (Mestrado) – Departamento de Engenharia de Materiais, Escola de Engenharia de São Carlos, Universidade de São Paulo, São Carlos, 2014. Ferritic alloy steels with chromium and molybdenum, as ASTM A335 P22, are widely used in steam generators in power plants around the world and may have broken fatigue during operation. The assembly of the components of the steam generators in the field is performed by manual welding techniques and has been identified as a critical factor for the quality of these devices when some parameter is ignored during the welding process. The welded region of an alloy is influenced thermal cycle during welding, alloying elements present in the steel and weld metal increases hardenability, and thus favors the formation of bainíticas or martensitic microstructures in the welded region. In this study, a weld made according to the procedure qualified, pre-heating and post-weld relief of stress was compared with a weld treatments performed without preheating and relieving stress, and was further compared with a solder heat treatments performed without preheating and stress relief heat input and determined by the above procedure. For this, the performance of each weld was analyzed for performance in tensile tests, lateral bending (qualification requirements of ASME IX by procedure code), and testing of Charpy impact resistance and toughness of each major region of the fracture weld (base material, HAZ and weld metal). The fracture toughness of each region was determined by fracture mechanics technique of elastic-plastic fracture Crack Tip Open Displacement (CTOD) applied to ductile materials. The result of this comparative study shows that even neglecting the parameters limits of the welding procedure specified for ASTM A335 P22 with thickness of 21mm and diameter of 304.8 mm, the procedure would have passed in qualification tests established by ASME IX (tensile and lateral bending). However, the results of Charpy impact and the CTOD tests performed in weld regions showed that the weld metal had a very low tenacity than was observed in the HAZ and the base material. Thus the realization of pre-heating and postweld treatment relief produced microstructures with lower hardness but that was not reflected in an increase in the toughness of weld metal.

Determinação da tenacidade à fratura da região da solda de um tubo de aço ferrítico ASTM A 335 Gr.P22 através do Deslocamento da Abertura da Ponta da Trinca (CTOD)