Examination of Coil Pipe Butt Joint Made of 7CrMoVTiB10-10(T24) Steel After Service

2012 ◽  
Vol 57 (2) ◽  
pp. 553-557 ◽  
Author(s):  
G. Golański ◽  
P. Gawień ◽  
J. Słania
Keyword(s):  
Heat Treatment ◽  
Grain Boundaries ◽  
Contact Area ◽  
High Stability ◽  
Welded Joint ◽  
High Hardness ◽  
Butt Joint ◽  
Post Weld Heat Treatment ◽  
Weld Heat

Examination of Coil Pipe Butt Joint Made of 7CrMoVTiB10-10(T24) Steel After Service The paper presents the results of examination of coil pipe butt joint made of 7CrMoVTiB10-10 steel (T24). Tested joint was in service for approximately 12 000 hours at the temperature of 540°C and pressure of 5.48MPa. Tests have revealed that the structure of all regions of the homogenous welded joint are correct and without any welding imperfections. Operation of the weld contributed mainly to advantaged precipitation of carbides especially on grain boundaries - frequently in the contact area of three grains' boundaries as well as in the form of continuous network of precipitates. The measurement showed high hardness of the weld, what indicates high stability of the microstructure. It makes possible to find that post-weld heat treatment is indispensable.

Effect of post-weld heat treatment on inhomogeneity of aluminum/copper rotary friction welded joint

2018 ◽  
Vol 5 (9) ◽  
pp. 096504 ◽  
Author(s):  
Peng Li ◽  
Longwei Pan ◽  
Xiaohu Hao ◽  
Shuai Li ◽  
Honggang Dong
Keyword(s):  
Heat Treatment ◽  
Welded Joint ◽  
Post Weld Heat Treatment ◽  
Weld Heat

Effect of Post Weld Heat Treatment on Weld Hardness Quality of P91 Welded Pipes

2015 ◽  
Vol 799-800 ◽  
pp. 377-381
Author(s):  
Mohd Amin Abd Majid ◽  
Muhammad Sarwar
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Residual Stresses ◽  
Weld Metal ◽  
Welded Joint ◽  
Post Weld Heat Treatment ◽  
Bead Geometry ◽  
Construction Sites ◽  
Weld Heat

Quality of a weld produced is generally evaluated by different parameters such as weld size, bead geometry, deposition rate, hardness and strength. A common problem that has been faced at the construction sites is to obtain a good welded joint having the required strength with minimal detrimental residual stresses to avoid any premature cracking due to high variation of hardness. In order to address this issue and to attain good weld quality, this study has been made to comprehend the effect of the post weld heat treatment on P91 material welds produced by TIG welding. Findings from the studies indicate that the PWHT has significant influence on the weld hardness of Alloy Steel-A335 P91 pipes. It is eminent that during cooling, after welding of P91, quenched martensite was formed in the HAZ that results in an increased hardness to an undesirable level of more than 250HB. PWHT at temperature of 760°C for 2 hours has good influence on mechanical properties as the hardness decreases and turns out to be uniformly distributed. If the PWHT is correctly carried out, the hardness of parent metals, heat affected zones and weld metal can be brought into the required limits to avoid any premature cracking due to high variation of hardness.

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