Mechanism Analysis for the Enhancement of Low-Temperature Impact Toughness of Nodular Cast Iron by Heat Treatment.

The low-temperature impact toughness of nodular cast iron can be significantly enhanced by heat treatment, and thus meet the severe service requirements in the fields of high-speed rail and power generation, etc. In order to explore the enhancement mechanism, microstructure, hardness, composition and other characteristics of as-cast and heat-treated nodular cast iron is systematically tested and compared by optical microscopy, microhardness tester, EBSD, SEM, electron probe, and impact toughness testing machine in this study. The results show that heat treatment has little effect on the morphology and size of graphite in nodular cast iron, ignores the effect on the grain size, morphology, and distribution of ferritic matrix, and has little effect on the hardness and exchange of elements, while it is meaningful to find that heat treatment brings about significant decrease in high-angle grain boundaries (HAGB) between 59° and 60°, decreasing from 10% to 3%.

The Effect of Novel Complex Treatment of Annealing and Sandblasting on the Microstructure and Performance of Welded TA1 Titanium Plate.

The welding titanium cathode roller has the obvious advantages of low cost, high efficiency, and no diameter restriction. Unfortunately, the longitudinal weld on the cathode roller adversely impacts the quality of the electrolytic copper foil due to the great difference between the microstructure of the weld zone and the base metal. Thus, it is crucial to reduce their difference by regulating the microstructure of the weld zone.

Strengthening of CoNiFeVMo Medium Entropy Alloy Wire Rods with Loading-Unloading Cycles.

Changes in the texture as well as mechanical properties of CoNiFeVMo medium entropy alloy wire rods during loading-unloading are investigated. The intensity of the recrystallization texture {001}<110> component and fraction of low angle grains increase with the loading-unloading cycles and the alloy strength increases (934 MPa to 1083 MPa) due to dislocation increment in the loading-unloading cycles. The loading modulus (E) and average modulus (E) for a hysteresis loop decrease slightly, whereas the unloading modulus (E) increases, the Eun increment of 5-TC-UTand 10-TC-UT are 22 and 137 GPa.