Strength gradient enhances fatigue resistance of steels
نویسندگان
چکیده
Steels are heavily used in infrastructure and the transportation industry, and enhancing their fatigue resistance is a major challenge in materials engineering. In this study, by introducing a gradient microstructure into 304 austenitic steel, which is one of the most widely used types of stainless steel, we show that a strength gradient substantially enhances the fatigue life of the material. Pre-notched samples with negative strength gradients in front of the notch's tip endure many more fatigue cycles than do samples with positive strength gradients during the crack initiation stage, and samples with either type of gradient perform better than do gradient-free samples with the same average yield strength. However, as a crack grows, samples with positive strength gradients exhibit better resistance to fatigue crack propagation than do samples with negative gradients or no gradient. This study demonstrates a simple and promising strategy for using gradient structures to enhance the fatigue resistance of materials and complements related studies of strength and ductility.
منابع مشابه
The Influence of Ultrasonic Impact Treatment on Fatigue Behaviour of Welded Joints in High-strength Steel
The unabated growth of the steel industry and progressively increasing operating loads on metal structures generate a need for a search for optimum engineering solutions to improve the loadcarrying capacity and reduce metal consumption. One way of resolving this problem is to utilise high-strength steels. It is common knowledge however that the improvement of the steel strength is accompanied b...
متن کاملThe Effect of Ferrite Grain Size on the Fatigue Behavior of Ferrite-martensite Dual-phase Steels
The effect of ferrite grain size on the fatigue and tensile properties of dual phase steels with a 0.25 volume fraction of martensite (Vm) under different heat treatments was investigated. The heat treatments were homogenized at 1200 oC along with several subsequent normalizations at 910 oC, resulting in different microstructures and mechanical properties. After heat treatment, the obtained ste...
متن کاملOn the Improvement of the Fatigue Behaviour of Austenitic Stainless Steels Due to Surface Residual Stresses Produced by Low Temperature Carburizing
Low temperature carburizing (LTC) treatment improves surface hardness and wear resistance of the austenitic stainless steels without reducing their corrosion resistance. Surface hardness over 1000 Vickers and compressive residual stresses whose modulus exceeds 1500 MPa are usually achieved in the carburized layer, thanks to the formation of the so-called “S-phase”, a carbonsupersaturated austen...
متن کاملNiobium Alloyed High Strength Steels for Automotive Applications
Modern vehicle bodies make intensive use of high strength steel grades to meet the contradicting demand of lighter weight and simultaneously better mechanical performance. For many steel grades microalloying by niobium is the key to achieve their characteristic property profile. In HSLA steels niobium enhances the strength primarily by grain refinement. In interstitial free high strength steels...
متن کاملEffects of Plasma ZrN Metallurgy and Shot Peening Duplex Treatment on Fretting Wear and Fretting Fatigue Behavior of Ti6Al4V Alloy
A metallurgical zirconium nitride (ZrN) layer was fabricated using glow metallurgy using nitriding with zirconiuming prior treatment of the Ti6Al4V alloy. The microstructure, composition and microhardness of the corresponding layer were studied. The influence of this treatment on fretting wear (FW) and fretting fatigue (FF) behavior of the Ti6Al4V alloy was studied. The composite layer consiste...
متن کامل