Induction Hot Bending and Heat Treatment of 20” API 5L X80 Pipe

Author(s):  
Gilmar Zacca Batista ◽  
Leonardo Naschpitz ◽  
Eduardo Hippert ◽  
Ivani de Souza Bott

The present work discusses the effect of the induction hot bending process on the microstructure and the mechanical properties of an API 5L X80, 20” pipe produced by the UOE process. The key characteristic of the pipe was the manufacturing process of the steel plate, involving thermomechanical controlled rolling without accelerated cooling. The pipe bending was carried out applying local induction heating followed by water quenching and a further temper heat treatment which was applied to the curved section. The methodology of analysis compared the curved section with the original body pipe (tangent end), taking into account dimensional analysis, microstructural evaluation and mechanical tests which included Charpy-V impact, tensile and microhardness. A significant microstructural change and decrease, not only in the transition temperature, but also in the yield strength, occurred after induction bending. This reduction resulted in a tensile strength below the standard requirements. The subsequent tempering heat treatment applied to the curved section produced an increase in the yield strength to achieve the API 5L requirements for this class of steel.

Author(s):  
O. B. Berdnik ◽  
I. N. Tsareva ◽  
M. K. Chegurov

This article deals with structural features and characteristic changes that affect the mechanical characteristics after different service life in real conditions using the example of the blades of the 4th stage of turbine GTE-45-3 with an operating time of 13,000 to 100,000 hours. To study the change in the state of the material under different operating conditions, determine the degree of influence of heat treatment on the regeneration of the microstructure, and restore the mechanical characteristics of the alloy after different periods of operation, non-standard methods were used: relaxation tests on miniature samples to determine the physical yield strength and microplasticity limit and quantitative evaluation of the plasticity coefficient of the material from experimental values of hardness, which allow us to identify the changes occurring in the microvolumes of the material and predict the performance of the product as a whole.


Author(s):  
O. V. Sych

On the basis of the conducted research, a complex of scientific and technological methods has been developed for various technological processes (thermomechanical processing with accelerated cooling, quenching from rolling and separate furnace heating with high-temperature tempering). The developed method provides the formation of the structure of acceptable heterogeneity and anisotropy according to different morphological and crystallographic parameters throughout the thickness of rolled products up to 100 mm from low alloy steels with a yield strength of at least 315–460 MPa and up to 60 mm from economically alloyed steels with a yield strength of at least 500–750 MPa. The paper presents results of the industrial implementation of hot plastic deformation and heat treatment schemes for the production of cold rolled steel sheet with yield strength of at least 315–750 MPa for the Arctic. The structure of sheet metal thickness is given, providing guaranteed characteristics of strength, ductility, cold resistance, weldability and crack resistance.


Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 127
Author(s):  
Zichen Liu ◽  
Xiaodong Hu ◽  
Zhiwei Yang ◽  
Bin Yang ◽  
Jingkai Chen ◽  
...  

In order to clarify the role of different post-weld heat treatment processes in the manufacturing process, welding tests, post-weld heat treatment tests, and finite element analysis (FEA) are carried out for 12C1MoV steel pipes. The simulated temperature field and residual stress field agree well with the measured results, which indicates that the simulation method is available. The influence of post-weld heat treatment process parameters on residual stress reduction results is further analyzed. It is found that the post weld dehydrogenation treatment could not release residual stress obviously. However, the residual stress can be relieved by 65% with tempering treatment. The stress relief effect of “post weld dehydrogenation treatment + temper heat treatment” is same with that of “temper heat treatment”. The higher the temperature, the greater the residual stress reduction, when the peak temperature is at 650–750 °C, especially for the stress concentration area. The longer holding time has no obvious positive effect on the reduction of residual stress.


Author(s):  
Mehdi Soltan Ali Nezhad ◽  
Sadegh Ghazvinian ◽  
Mahmoud Amirsalehi ◽  
Amir Momeni

Abstract Three steels were designed based on HSLA-100 with additional levels of Mn, Ni, Cr and Cu. The steels were prepared by controlled rolling and tempered at temperatures in range of 550–700°C. The continuous cooling time curves were shifted to longer times and lower temperatures with the increased tendency for the formation of martensite at lower cooling rates. The microstructures revealed that controlled rolling results in austenite with uniform fine grain structure. The steel with the highest amount of Mn showed the greatest strength after tempering at 750 °C. The top strength was attributed to the formation of Cu-rich particles. The steel with 1.03 wt.% Mn, tempered at 650 °C exhibited the best Charpy impact toughness at –85°C. On the other hand, the steel that contained 2.11 wt.% Mn and tempered at 700 °C showed the highest yield strength of 1 097.5 MPa (∼159 ksi) and an impact toughness of 41.6 J at –85°C.


Author(s):  
Sagar Sarkar ◽  
Cheruvu Siva Kumar ◽  
Ashish Kumar Nath

One of the most popular additive manufacturing processes is laser based direct metal laser sintering process which enables us to make complex three dimensional parts directly from CAD models. Due to layer by layer formation, parts built in this process tend to be anisotropic in nature. Suitable heat treatment can reduce this anisotropic behaviour by changing the microstructure. Depending upon the applications, a wide range of mechanical properties can be achieved between 482–621° C temperature for precipitation-hardened stainless steels. In the present study effect of different heat treatment processes, namely solution annealing, ageing and overaging, on tensile strength, hardness and wear properties has been studied in detail. Suitable metallurgical and mechanical characterization techniques have been applied wherever required, to support the experimental observations. Results show H900 condition gives highest yield strength and lowest tensile strain at break whereas solution annealing gives lowest yield strength and as-built condition gives highest tensile strain at break. SEM images show that H900 and H1150 condition produces brittle and ductile morphology respectively which in turn gives highest and lowest hardness value respectively.XRD analysis shows presence of austenite phases which can increase hardness at the cost of ductility. Average wear loss for H900 condition is highest whereas it is lowest for solution annealed condition. Further optical and SEM images have been taken to understand the basic wear mechanism involved.


2003 ◽  
Vol 89 (6) ◽  
pp. 705-710 ◽  
Author(s):  
Yomei YOSHIOKA ◽  
Hiromichi ITOU ◽  
Yasuhiko TANAKA ◽  
Yasumi IKEDA

2007 ◽  
Vol 546-549 ◽  
pp. 825-828 ◽  
Author(s):  
Man Jin ◽  
Jing Li ◽  
Guang Jie Shao

The precipitation behaviors and microstructures of nano-precipitates in AA6082 Al-Mg-Si alloy with and without Cu additions during heat treatment process were studied using hardness measurements, TEM, mechanical tests and 3DAP. Meanwhile, the softening process of 6082 alloys with Cu and without Cu, isothermally conditioned at 250°C, has also been investigated. It was found that the rate of age hardening, mechanical properties and thermal stability are higher for the Cu-containing alloy. The TEM and 3DAP observations showed that Q’ precipitates were existed after aged at 170°C for 8h in the alloy with Cu addition. Comparing the hardness, mechanical properties and thermal stability curves, it was concluded that the Q’ precipitates play a major role in improving the age hardening kinetics and properties of 6082 alloy with Cu addition.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1883 ◽  
Author(s):  
Chao Peng ◽  
Guangxue Chen

In this study, poly(vinyl alcohol) (PVA) composite films enhanced by α-chitin nanowhiskers (ChWs) were prepared through heat treatment. The obtained membranes were assessed by means of FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis, regular light transmittance, mechanical tests, permeability and water absorption. The influence of the nano-component and heat treatment on the mechanical, thermal and water-resistant properties of the composite membrane were analyzed. From the results of the work, the produced films with excellent barrier properties and inexpensive raw processed materials have great prospects in packaging applications.


Sign in / Sign up

Export Citation Format

Share Document