Tag Archives: martensite

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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Comparison of Case Hardening by Carburizing Versus Surface Induction Hardening

In past postings, the case and core properties of case hardened steels have been discussed.  These discussions have included the fatigue properties of both carburized and surface induction hardened steels. Carburizing is usually employed on carbon or low alloy steels … 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 Properties of Case-Carburized SAE 8620

In recent postings, the strain-controlled fatigue properties of the high-hardness case and the lower-hardness core of carburized low-alloy steels were compared.  The properties of the case were developed through simulation by diffusing carbon completely through fatigue-specimen blanks. The properties of … 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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Further Comparisons of the Case and Core Properties of Induction Hardened Steels

In the last posting, the fatigue properties of surface induction hardened 1050 axle shafts were presented.  Strain life data showed that in the short life regime, the fatigue properties of the low hardness core were better than those of the … Continue reading

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