Comparative study of phase transformation temperatures in high strength steel weld metals

2017 ◽  
Vol 59 (4) ◽  
pp. 344-347 ◽  
Author(s):  
Rahul Sharma ◽  
Uwe Reisgen
2010 ◽  
Vol 24 (12) ◽  
pp. 903-910 ◽  
Author(s):  
Humberto N. Farneze ◽  
Jorge Carlos F. Jorge ◽  
Luís Felipe G. de Souza ◽  
Ivaní de S. Bott

Author(s):  
Walker A. S. Filho ◽  
Guilherme M. S. Silveira ◽  
Jeferson F. M. Costa ◽  
Matheus C. Mendes ◽  
Luís Felipe G. de Souza ◽  
...  

2021 ◽  
Vol 100 (12) ◽  
pp. 410-420
Author(s):  
KRISHNA SAMPATH ◽  

Recently, Dr. Glyn M. Evans posted a large shielded metal arc (SMA) weld metal (WM) database on the ResearchGate website (researchgate.net). This database contains more than 950 WM compositions, along with their respective WM tensile and Charpy V-notch (CVN) impact properties. In particular, the CVN impact properties list the test temperatures that achieved 28 and 100 J impact energy for each WM composition. While the availability of this SMA WM database is a valuable and rare gift to the welding community, how could the welding community analyze this database to gain valuable insights? This paper utilizes a constraints-based model (CBM) as a simple and effective framework to organize and analyze this very large Fe-C-Mn SMA WM database. A CBM is built on the metallurgical principle that one needs to lower relevant solid-state phase transformation (i.e., austenite decomposition) temperatures to improve WM strength and fracture toughness while simultaneously reducing carbon content and Yurioka’s carbon equivalent number (CEN) to improve the weldability of high-strength steels. To this end, a CBM identifies and simultaneously solves several statistical (regression) equations that relate the chemical composition of high-strength steel WM with Yurioka’s CEN and selected solid-state phase transformation temperatures related to austenite decomposition. The results of the current effort demonstrate that the analysis of Evans’s shielded metal arc welding database using a CBM as a framework reaffirms that controlling carbon content, the value of the CEN, and calculated solid-state phase transformation temperatures, particularly the difference between the calculated Bs (bainite-start) and Ms (martensite-start) temperatures, is critical to developing and identifying high-performance, high-strength steel welding electrodes. A dual approach that manipulates the contents of principal alloy elements such as C, Mn, Ni, Cr, Mo, and Cu, and adds controlled amounts of Ti, B, Al, O, and N, appears to offer the best means to lower relevant solid-state phase transformation temperatures to produce high-strength and high-toughness WMs.


2013 ◽  
Vol 758 ◽  
pp. 21-32 ◽  
Author(s):  
Antonio José Mendes Gomes ◽  
Jorge Carlos Ferreira Jorge ◽  
Luís Felipe Guimarães de Souza ◽  
Ivani S. Bott

The present work is part of a wide research program which the main goal is the development of welding procedures for chain and accessories for application in mooring systems of oil platforms. In the specific case of the work in subject, the development of different covered electrodes formulations is discussed for obtaining high mechanical strength and impact toughness, of the order of 860 MPa and 50 joules at –20°C, respectively. Welded joints using the developed electrodes were prepared for evaluation of the mechanical properties, using preheat of 200°C, direct current, flat position and heat input of 1.5 kJ/mm. After welding, tensile, impact Charpy-V and hardness tests were performed in specimens removed integrally from the weld metal, both in as welded and heat treated conditions. The post weld heat treatment (PWHT) was conducted at 600°C for 1, 2 and 3 hours. The results shows that the obtained weld metals have mechanical properties higher than the minimum required for the welding of a IACS W22 R4 Grade steel, and particularly good impact properties, which indicates that the correct control of the chemical composition, particularly, of Mn-Ni balance, makes possible to achieve an adequate strength/toughness relationship for high strength steel weld metals, where the PWH is mandatory. In addition, it was verified that the increase in the time of PWHT did not promote substantial impairment on mechanical properties.


Sign in / Sign up

Export Citation Format

Share Document