Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Development of an equipment to evaluate the susceptibility to hydrogen assisted cracking
Submission Author:
Guilherme Martiniano , MG
Co-Authors:
Danilo Souza, José Eduardo Silveira Leal, Sinésio Franco, Guilherme Martiniano
Presenter: Guilherme Martiniano
doi://10.26678/ABCM.COBEM2017.COB17-0747
Abstract
Hydrogen embrittlement of metallic materials has been a frequent problem in different industry sectors. Because it is the smallest existing atom, hydrogen diffuses into the microstructure of metallic materials, resulting in internal mechanical stresses that may eventually lead to a catastrophic failure. The most common methods available to analyze this phenomenon are time consuming and expensive. For this reason, it is desired to develop a test method that does not have such disadvantages. In this work it is presented the development of an equipment to rapidly evaluate the susceptibility to hydrogen embrittlement (SHE) of the metallic materials using the rising step load (RSL) bending test in assisted environment, which is governed by the ASTM Standard F1624. This equipment has a great advantage over the other evaluation methods of SHE, which is the shortest test time to have representative results. The validation of the infrastructure was performed by using unnotched AISI 4140 steel quenched and tempered samples, whose measured mechanical stress was compared to that returned by the RSL software and the results showed errors lower than 1 %. The tests to verify the performance of the RSL equipment were carried out on notched samples of quenched and tempered AISI 4140 steel with a hardness of 40HRC. The effect of the cathodic potential on the SHE was also evaluated. The results showed a direct relationship between the cathodic potential variation and the SHE of the sample, with stabilization of SHE at -1.1 VAg/AgCl. In addition, the tests showed also an increase in SHE with increasing material hardness.
Keywords
Hydrogen embrittlement, rising step load, cathodic protection, fracture strength
