Effect of pipe production conditions and material structure state on operation reliability of high-strength pipe steels

Author(s):  
A. R. Mishet’yan ◽  
I. P. Shabalov ◽  
O. N. Chevskaya ◽  
G. A. Filippov
Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 80 ◽  
Author(s):  
Mykola Chausov ◽  
Janette Brezinová ◽  
Andrii Pylypenko ◽  
Pavlo Maruschak ◽  
Liudmyla Titova ◽  
...  

A simple technological method is proposed and tested experimentally, which allows for the improvement of mechanical properties in sheet two-phase high-strength titanium alloys VT23 and VT23M on the finished product (rolled metal), due to impact-oscillatory loading. Under impact-oscillatory loading and dynamic non-equilibrium processes (DNP) are realized in titanium alloys, leading to the self-organization of the structure. As a result, the mechanical properties of titanium alloys vary significantly with subsequent loading after the realization of DNP. In this study, the test modes are found, which can be used in the production conditions.


Author(s):  
Akihide Nagao ◽  
Nobuyuki Ishikawa ◽  
Toshio Takano

Cr-Mo and Ni-Cr-Mo high-strength low-alloy steels are candidate materials for the storage of high-pressure hydrogen gas. Forging materials of these steels have been used for such an environment, while there has been a strong demand for a higher performance material with high resistance to hydrogen embrittlement at lower cost. Thus, mechanical properties of Cr-Mo and Ni-Cr-Mo steels made of quenched and tempered seamless pipes in high-pressure hydrogen gas up to 105 MPa were examined in this study. The mechanical properties were deteriorated in the presence of hydrogen that appeared in reduction in local elongation, decrease in fracture toughness and accelerated fatigue-crack growth rate, although the presence of hydrogen did not affect yield and ultimate tensile strengths and made little difference to the fatigue endurance limit. It is proposed that pressure vessels for the storage of gaseous hydrogen made of these seamless line pipe steels can be designed.


1966 ◽  
Vol 88 (2) ◽  
pp. 480-488 ◽  
Author(s):  
R. V. Milligan ◽  
W. H. Koo ◽  
T. E. Davidson

The object of this work was to evaluate quantitatively the Bauschinger effect in a 4330 modified steel as a function of strength level and structure as derived from variations in heat-treatment. Material having martensitic, pearlitic, and bainitic structures was studied utilizing a uniaxial tension-compression specimen. Various ways of defining the magnitude of the Bauschinger effect are explained. One is a conventional approach as suggested by Welter, the other a technique which takes strain-hardening into account. The results show the Bauschinger effect to be independent of yield strength for three different strength levels of the martensitic material. It is only mildly influenced by material structure and independent of the direction of overstrain. The Bauschinger effect increases with increasing permanent strain up to approximately 2 percent and thereafter remains essentially constant.


CORROSION ◽  
1986 ◽  
Vol 42 (6) ◽  
pp. 337-345 ◽  
Author(s):  
K. Matsumoto ◽  
Y. Kobayashi ◽  
K. Ume ◽  
K. Murakami ◽  
K. Taira ◽  
...  

Metallurgist ◽  
2011 ◽  
Vol 55 (7-8) ◽  
pp. 489-495 ◽  
Author(s):  
M. Yu. Matrosov ◽  
O. P. Talanov ◽  
I. V. Lyasotskii ◽  
D. L. Dyakonov ◽  
E. I. Khlusova ◽  
...  

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