Effect of the hydrogen outgassing time on the hardness of austenitic stainless steels welds

Godoi, Walmor Cardoso; Kuromoto, Neide K.; Guimarães, Ari Sauer; Lepienski, C.M.

doi:10.1016/s0921-5093(03)00014-5

Cited by 27 publications

(8 citation statements)

References 11 publications

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“…They found that cathodic hydrogen charging produced major surface hardening. In general, hydrogen charging increases hardness of metallic materials (plain carbon steels, austenitic stainless steels, stainless steels, Ti alloy) [3,[35][36][37], but for some alloys a limited effect on hardness, or even opposite effect: H-induced softening, was observed [38].…”

Section: Ailure Analysis Of Boiler Tubementioning

confidence: 99%

Hydrogen damage of steels: A case study and hydrogen embrittlement model

Djukic

Zeravcic

Bakić

et al. 2015

Engineering Failure Analysis

281

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Section: Ailure Analysis Of Boiler Tubementioning

confidence: 99%

Hydrogen damage of steels: A case study and hydrogen embrittlement model

Djukic

Zeravcic

Bakić

et al. 2015

Engineering Failure Analysis

281

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“…Chapetti et al reported that the lower bainitic or martensitic weld metal is marginally susceptible to hydrogen embrittlement in ERW X46 linepipe steels, [6] but hydrogen in welding region is related to the degradation of mechanical properties. [28,29] With reasonable doubts, we evaluated the diffusible hydrogen contents in the investigated steel pipes. Figure 11 shows the TDS [27] results.…”

Section: Diffusible Hydrogen Content and Effective Stress In The Wmentioning

confidence: 99%

A Study of Metallurgical Factors for Defect Formation in Electric Resistance Welded API Steel Pipes

Joo

Noh

Kim

et al. 2015

Metallurgical and Materials Transactions E

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A critical assessment has been made for the electric resistance welded API-J55 and P110 steel pipes to clarify the metallurgical factors crucial to the occurrence of welding defects. Electric resistance welding (ERW) is widely accepted due to its low cost and high efficiency of production as a conventional manufacturing technology for the steel pipes. However, ERW pipes are vulnerable to the defect formation because its welding zone has different characteristics compared to the base material. It has been found that there were two major crack types in the investigated steels: surface crack and hook crack (J-shaped crack). Macroscopic examinations suggested that the causes and occurrences of the cracks were distinct among the investigated steels. The small surface cracks were largely occurred in the API-J55 steel pipes. The microstructure in the vicinity of crack was identical to the matrix, but it was found that the formation of the surface cracks was attributed to the sulfur and oxide inclusions. The energy dispersive X-ray spectroscopy (EDS) analysis showed that the cracks were associated with hydrogen and clusters of complex oxide inclusions with calcium such as Al-Ca-O and Fe-Ca-O. Moreover, sulfur was found to be the major culprit for the surface crack formation in the statistical evaluation. On the other hand, most of the hook cracks were large in size and occurred in the API-P110 steel pipes even though the sulfur level was very low, where the phosphorous was critical to the occurrence of hook crack. Although the EDS analysis showed the similar oxides compared to the case of surface cracks, B and P segregation were found in secondary ion mass spectrometry and electron probe micro analyzer analyses. In the vicinity of the hook cracks, martensite (locally hardened microstructure) was formed because the segregation enhances the hardenability. Eventually, the crack propagates along the martensite which was the band of ferrite and pearlite. It is postulated that the hook crack in API-P110 steel pipes is initiated from the oxides with hydrogen and propagated along the banded microstructure with the prior austenite grain boundaries where culprit elements can be segregated.

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“…This hardness reduction is attributed to crack nucleation during the hydrogen outgassing. The outgassing process induces the martensitic transformation from hcp e 0 to bcc a 0 phases [7]. For the 27% N sample, the hardness after hydrogenation reduces from 14.4 GPa to 8.2 GPa.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

“…The a 0 -martensite promotes crack formation that grows with the outgassing time. As a consequence, it is observed that crack formation induces a hardness decrease at surface [7].…”

Section: Introductionmentioning

confidence: 99%