The effect of nickel on the Sulfide Stress Cracking (SSC) resistance of three modified AISI 4340 steels containing 0, 1 and 2% Ni as a function of tempering temperature and microstructure was evaluated. The results of SSC tests, light microscopy, continuous yielding behavior during tensile deformation, along with fracture surface characterizations, were used to correlate the reduction in SSC resistance with microstructural variations due to nickel. By limiting the variables in this experiment, variations in SSC resistance are shown to be related to localized microstructural changes (i.e., the presence of untempered martensite) through metallographic and mechanical property observations. Restrictions placed on a material based on hardness and nickel content are shown to be ineffective for predicting SSC resistance. A tempering equation that yields satisfactory SSC performance for nickel low-alloy steels is also presented.

Subject
Materials, Critical temperature, Secondary cracks, Tempering temperature, Microstructure, Nickel content, Mechanical failure, Steel, Nickel, Sulfide stress cracking, Tempering, Austenite, Martensite
Keywords:
SSC, nickel, AISI 4340, tempering, microstructure, tensile, fractography
© 1995 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
1995
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.