Tag Archives: fatigue

Additional Data on the Effect of Cooling Rate on the Fatigue Properties of Carburized Steels

In the previous post, the effects of a cooling rate change after carburizing, due to a change in steel bar diameter, on core fatigue properties was examined.  The data was developed for a Ni-Cr-Mo low alloy steel (SAE 4320), and … Continue reading

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Effect of Cooling Rate after Carburizing on the Fatigue Properties of Carburized Steels

In earlier posts, the fatigue properties of various carburized low alloy steels were examined.  Both case and core properties were evaluated.  Since carburized components are manufactured in various section sizes, it can be expected that cooling rates in the cores … Continue reading

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Additional Effects of Sulfur on the Fatigue Properties of Low Alloy Steels

In the previous posting, it was shown that, as a result of the presence of elongated manganese sulfide inclusions, the fatigue properties of low alloy steels can exhibit directionally dependent behavior.  Fatigue properties obtained in a test direction transverse to … Continue reading

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The Effects of Sulfur on the Fatigue Properties of Low Alloy Steels

It is well known that sulfur has a major impact on some of the properties of low alloy steels.  Sulfur is present in the form of manganese sulfides, which are highly plastic at hot working temperatures.  As a result, during … Continue reading

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Comparison of Through-Induction Hardening with Conventional Hardening

Two methods are often used to through harden and low alloy steels.  The well recognized conventional hardening method involves heating to an appropriate austenitizing temperature for a specific length of time in a furnace with or without a protective atmosphere. This … Continue reading

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Hot Formed and Controlled Cooled Microalloyed Steels Compared to Quenched and Tempered Medium Carbon Steels

Microalloyed steels are often used in the as-formed or as-forged condition in applications where the use of medium carbon steels would require that the component be quenched and tempered.  Microalloyed steels, which contain small additions of niobium and/or vanadium, therefore … Continue reading

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Repeatability Study: SAE 4140 Steel

As part of the development of the Bar Steel Fatigue Database, AISI undertook a limited investigation to examine the amount of scatter that might be expected from fatigue data. Of particular concern was scatter that might result due to securing … Continue reading

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Fatigue Performance As Measured By Fatigue Strength Quenched and Tempered Steels

In a recent posting, a comparison of the fatigue properties for normalized steels (163-259 BHN) showed that the strain-life curves fell within a rather narrow band, especially in the long-life regime.  It was pointed out that, under a circumstance such … Continue reading

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Effect of Continuous Casting Practice on the Case and Core Properties of Carburized Alloy Steels

In the previous posting, the strain-controlled fatigue properties of the high-hardness case and low-hardness core of carburized SAE 4620 steel were compared.  It was shown that at short lives, the softer core exhibited better properties than the high-hardness case.  At … Continue reading

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Comparison of the Case and Core Properties of Carburized Steels

In recent postings, the strain-controlled fatigue properties of the high-hardness case and low-hardness core of induction hardened steels were compared.  It was shown that at short lives, the softer core outperformed the high-hardness case.  At long life, the fatigue properties … Continue reading

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