Session: MF-24-01 Matls & Fabrication for Refining-Toughness Issues in Alloys at Elevated Temperatures

Paper Number: 121725

121725 - Fracture Toughness of Cold Formed Heavy Wall Plates in 2 1/4 Cr 1 Mo 1/4 V 

The 2 ¼ Cr 1Mo ¼ V is widely applied for the design of high pressure and temperature equipment.

For large and heavy wall pressure equipment the cylindrical shell barrels can be carried either by forging or by plate rolled to achieve the required dimensions.

Plate forming may have an impact on the material properties based upon temperature and deformation level for the involved plate thickness. Some specification claims for a preheating temperature to be applied during plate forming of low alloy steel. Such preheating in case of heavy wall plate thickness and inherent overall large dimensions has to be carried out in furnace with difficulties to keep the required temperature during the whole forming sequence and with inherent impact on the fabrication schedule; a significant amount of gas consumption is envisaged.

A test campaign has been launched to investigate the real necessity of such preheating by forming of test plate coupons at different deformation levels with and without preheating. The base material selected was a low alloy 2,25 Cr 1 Mo Vanadium modified steel for which a preheating temperature of 177°C (minimum) is generally requested.

After forming, non-destructive examinations have been carried out followed by conventional mechanical test such as tensile strength and impact test aimed to investigate the resulting plate quality among the different forming conditions.

Material soundness can be impaired by existing flaws such as cracks, voids and metallurgical inclusions.

In order to better investigate the potential risk of crack propagation from existing defect under the applied stress, fracture mechanics tests according to ASTM E1820 have been carried out to identify any possible different crack propagation behaviour, by forming at room temperature and at preheating temperature of 177°C.

In this work the test campaign and the obtained results are presented, analysed and discussed.

Presenting Author: Marco Palombo Istituto Italiano Saldatura

Presenting Author Biography: Marco Palombo graduated in Science and Engineering of Materials at Università degli Studi di Genova (University of Genoa) in 2009, in 2014 he graduated PH.D in Sciences and Technologies of Chemistry and Materials at Università degli Studi di Genova. He started to work in Columbus Supercoductors in 2009 and he get expertise in superconductors synthesis and fabrications of wires. In the 2012 he switched to Istituto Italiano della Saldatura, IIS (Italian Institute of Welding) and he focused on mechanical tests, fracture mechanics, creep, fatigue, failure analysis, and test engineering. In 2012 he graduated as International Welding Engineer (IWE) at IIS and today he is in charge at the department of Characterization and Qualification of Joints, Materials and Test Engineering of IIS. Since 2022, he is also the Technical Director of H2 IIS SIDER srl, a laboratory dedicated to testing under gaseous hydrogen environment up to 1500 bar of pressure.

Authors:

Marco Palombo Istituto Italiano Saldatura
Giorgia Doni Belleli Energy CPE
Stefano Sandon IIS Service srl
fausto fusari Belleli Energy Cpe