Abstract: The effect of cryogenic treatment on the mechanical and magnetic properties of WC–6% Co Ultrafine cemented carbides has been investigated in this paper. The results show that after the cryogenic treatment, the hardness slightly increases from 1750 to 1830, however, the transverse rupture strength decreases from 2510 MPa to 2480MPa. ,the magnetization decreased from 5.82% to 5.72%, decreasing 1.71%for 24 h, but the coercive force slightly increases and reaches the maximum of 24 kA/m for 2h.
Abstract: The strengthening treatment of carburized and subsequently niobiumized 40CrNiMo steel used for cutting pick has been discussed, and the microstructure and composition of niobiumizing layer are investigated by metallographic microscope, SEM and EDS, and XRD, which are compared with conventional strengthening treatment specimens in lab and working situation respectively. The results indicate that the main phases are NbC and Nb6C5 in the niobiumized layer, and the loss of weight of carburized and subsequently niobiumizing strengthening specimens is 58.4% of conventional strengthening ones ,and the working service life of cutting pick is increased by 69.0% ~ 78.1%.
Abstract: This work studied the interaction between carbide precipitation and impurity segregation under temper embrittlement (TE) conditions in a coarse-grained heat-affected zone (CGHAZ) in Q690 steel, a low-alloy high-strength structural steel used in the hydraulic support in the fully-mechanized mining face. From the perspective of carbide precipitation, through thermodynamics calculation and analysis, it was found that the existence of cementite at the grain boundaries was preceded by impurities segregation (primarily phosphorus). The precedent phosphorus segregation thus enhances the nucleation rate of cementite at the grain boundaries by lowering the ferrite/cementite interfacial energy. Both carbide precipitation and impurity segregation at the grain boundaries reached a maximum as a result of their mutual role in the temperature range of TE.
Abstract: the living environment of people increasingly demanding, architectural decoration only simple demined formal beauty from the past and nowadays gradually develop into a comprehensive discipline, including energy-saving, environment protection and beauty. This paper is starting from the perspective of the development of building energy conservation, and is to make architectural decoration construction environment as a starting point to explore the application and development of environment-friendly building materials and energy-saving. And in the end it makes the prospect of building decoration materials.
Abstract: Based on the nonlinear FE platform ABAQUS, an elastic plastic 3D-FE model of 0Cr21Ni6Mn9N stainless steel tube was established to simulate the whole process, and its reliability was validated by experiment. Using the model, the effect of bending speed on forming quality was studied and the influence laws of bending speed on wrinkling wave ratio, wall thinning, cross section deformation and springback angle were revealed. The results show that the wrinkling wave ratio and springback angle decrease with the increasing of bending speed, while the effect of bending speed on wall thinning and cross section deformation are not significant. The maximum cross section deformation degree presents in the vicinity of the bending angle 30° along the bending direction and its position is almost unchanged with the variation of bending speed.
Abstract: Hot compression tests of AZ61 magnesium alloy were performed on gleeble1500D at strain rate ranged in 0.01~1s-1 and deformation temperature 350~400°C.The results show that the flow stress and microstructures strongly depend on the deformation temperature and the strain rate. When the temperature was reduced and the strain rate was enhanced, the area after dynamic recrystallization was enhanced, and the average dynamically recrystallied grain size reduce. But the dynamically recrystallied grain size was not well-proportioned. In this paper the 350°C×1s-1 was suggested.
Abstract: The ZK60 magnesium alloys add Y were deformed with extrusion simulation system, and extruded products for various heat treatment processes. The mechanism properties of Y element in ZK60 and its effect on microstructure were analyzed. as well as heat treatment process for ZK60 and ZK60 +1.0Y two influence of alloy microstructure and properties were investigated. The results showed that the addition of rare earth Y can effectively refine the grain ZK60 alloy, and can significantly improve the performance of ZK60 alloy plasticity. Artificial aging treatment can improve ZK60 and ZK60 +1.0Y alloy yield strength and ductility, the best artificial aging treatment ZK60 and ZK60 +1.0Y alloy extrusion products for the 180°C×24h.
Abstract: Several kinds of Glass Fiber Reinforced Polymer (GFRP) bars with different winding materials were manufactured through modifying the production process. Based on the experiments, compression and bending properties were tested. Through the observation of experiment phenomenon and the analysis of test date, the influence and mechanism from different winding materials are discussed. The test results that winding materials affect the compressive strength and bending strength of GFRP bars to a certain extent.
Abstract: In this work, the thermal spraying sacrificial anode was investigated as reinforced concrete structure cathodic protection method. During our experiment, the performance of the thermal spraying sacrificial anode was studied using electrochemical method, metallographic microscopy method and simulation tests. And the results show that the thermal spraying sacrificial anodes are better than traditional sacrificial anodes. The method of thermal spraying applied in sacrificial anode field is successful, which solve the problem of insufficient driving initial potential of traditional sacrificial anode in the concrete structure.
Abstract: A three-dimensional finite element analysis model was developed using ABAQUS to simulate the temperature distributions of circular concrete filled steel tube reinforced concrete column in this paper. The influence of main parameters on the temperature distribution, such as heating time, section diameter, and steel tube diameter, was analyzed. This provides valuable information about structural fire resistance and structural behaviour of concrete filled steel tube reinforced concrete column structure under fire.