Investigation of key-hole weldability of line pipe steel grade x70m in terms of fracture toughness

Download

index.pdf

Date

2017

Author

Çağırıcı, Mehmet

Metadata

Show full item record

Item Usage Stats

207
views

217
downloads

Micro-alloyed and thermomechanically rolled HSLA line pipe steels promise optimum strength and toughness. Their microstructure contains generally globular and acicular ferrite. However, the heat induced by welding during line pipe fabrication alters the microstructure at the proximity of the fusion zone which affects indirectly microstructure of the heat affected zone, consequently the fracture toughness, is governed by the chemistry of the material and the thermal cycles during the welding process. In fabrication generally submerged arc welding (SAW) is applied. The hybrid plasma arc welding (HPAW) might save filler consumption and reduce the heat input of the process. The purpose of this work is to investigate weldability of X70M by using the key-hole based hybrid welding process by focusing on fracture toughness.

Subject Keywords

Plasma arc welding., Fracture mechanics., Electric welding., Steel alloys.

URI

http://etd.lib.metu.edu.tr/upload/12621035/index.pdf
https://hdl.handle.net/11511/26806

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

An Investigation on fatigue crack propagation in gas metal and hybrid plasma-gas metal arc weldments of AA5083-H111 Okan, Kemal; Gürbüz, Rıza; Yurtışık, Koray; Department of Metallurgical and Materials Engineering (2015) 5083 aluminum alloy among 5XXX series has the greatest strength and is commonly used for its good weldability, corrosion resistance and moderate strength. In this study, 5083-H111 aluminum alloy plates were joined by Gas Metal Arc Welding (GMAW) and Hybrid Plasma Arc Welding (HPAW) techniques. Mechanical strength of base metal (BM) and welded samples was examined using hardness, tensile and toughness tests. Crack propagation behavior of BM, GMA welded and HPA welded samples was investigated by fatigue crack...
Effects of heat input and thermal cycles to the fracture toughness of API 5L grade X70M steel welded by gas metal arc welding Erol, Eren; Gür, C. Hakan.; Department of Metallurgical and Materials Engineering (2019) High strength low alloy steels are widely used in line pipe applications since they have reasonably high strength and toughness due to their micro-alloying elements and production via thermomechanically controlled process. During welding of these steels, microstructures of the fusion zone and the heat affected zone consisting globular and acicular ferrite alter due to induced heat and thermal cycles. Consequently, changes in the microstructure affects the mechanical properties such as fracture toughness. Ga...
The comparison of microstructure and mechanical properties of a low carbon bainitic forging steel after isothermal transformation and direct cooling Balcılar, Muhammed Mustafa; Ögel, Bilgehan; Department of Metallurgical and Materials Engineering (2022-4-27) Bainitic forging steels have emerged in recent decades as an alternative to Quench and Temper steels due to their low cost and energy requirements and optimum combination of strength, ductility, and toughness. Although effect of continuous cooling on bainitic forging steels have been studied, the effect of isothermal transformation on microstructure and mechanical properties of microalloyed bainitic forging steels is an open field. A low carbon microalloyed bainitic forging steel is examined in this study, ...
Investigation on the ballistic performance of a dual phase steel against 7.62 mm AP projectile Ubeyli, Mustafa; DEMİR, TEYFİK; Deniz, Hueseyin; Yıldırım, Raif Orhan; KELEŞ, Ömer (2010-03-25) Dual phase steels have the potential to reduce the weight of structural components because of the improved mechanical properties obtained from the two phases: soft ferrite and hard martensite. In this study, the ballistic performance of a low carbon and low alloy steel was investigated in intercritically annealed conditions. To do this, intercritical heat treatments at three different temperatures were applied to the steel samples separately to get three groups of samples having various martensite volume fr...
INVESTIGATION OF THE MICROSTRUCTURAL AND MECHANICAL PROPERTIES OF DP500 AND DP700 QUALITY STEELS WELDED WITH DIFFERENT HEAT INPUTS Yılmaz, Kardelen; Ögel, Bilgehan; Batıgün, Caner; Department of Metallurgical and Materials Engineering (2023-1-25) In this study, effect of different heat input values from different welding techniques on microstructural and mechanical properties of Dual Phase (DP) steel DP500 and DP700 are evaluated. The welding operations were carried out manually by using Tungsten Inert Gas Welding (TIG), Metal Active Gas (MAG) Pulse Arc Welding and MAG Cold Metal Transfer (CMT) arc methods with keeping different heat inputs. The specimens were welded under specified conditions. They were initially evaluated by metallographic methods...

Citation Formats

M. Çağırıcı, “Investigation of key-hole weldability of line pipe steel grade x70m in terms of fracture toughness,” M.S. - Master of Science, Middle East Technical University, 2017.