The Effect Of The Size Of Coating Components In The Performance Of D600R Surfacing Electrode

The application of nanometer material in the field of welding is more and more extensive, which is mainly centralized in the field of welding materials (including the electrode material of TIG welding and covered electrode), welding structure, welding procedure, welding shield, and so on. Currently, nanometer electrode has been sold on the market, however, the systematic research about the effect mechanism of the nanometer material in the course of welding is extraordinarily rare, and the same as the study of the interaction of thinning certain components of coating on the surfacing electrode performance. Basing on the two points above, this paper adds fine powder materials of different size to the coating of D600R surfacing electrode in order to research the impact on electrode properties.Firstly, marble with different size and different proportion (refer to the proportion of fine marble powder to the total marble content in coating) was put into the coating of D600R surfacing electrode, then the electrodes were made. The effect of the size and the proportion of marble on the press performance and appearance quality of surfacing electrodes were discussed. By means of Thermal Analysis Technology the variation of weight and heat quantity of component from room temperature to 1500℃was determined. With the aid of GX High-Temperature Physical Function Determinator the melting temperature of coating was measured. The usability of electrodes was evaluated with the help of Hannover Analysator combining with the feeling of welding workers. The content of diffusible hydrogen in welded metal was determined according to the Glycerine method. The hardness and wear resistance of welded metal was tested using HR-150A Rockwell Hardness Tester and MM-200 Wear Testing Machine.It is indicated that the powder of electrode coating is apt to lump, but the appearance quality is better while adding fine marble powder. The usability of electrode is the best, when the size of marble is 56 nm and the proportion is 20～25 %. The melting temperature of coating is the lowest, when the proportion is 25%. With the constant increase of the proportion of nanometer marble to the total marble content, the content of diffusible hydrogen in welded metal become smaller, but the deposited efficiency turns to be higher. When the amount of nanometer marble (the size is 56 nm) is suitable, the transition of alloying elements will increase, and the hardness and wear resistance of welded metal will be heightened. At last we find that when the size of marble is 56 nm and the proportion is 25%, the performance of D600R hardfacing electrode is the best.Secondly, marble, titanium iron and rare earth silicon with different size and different proportion were put into the coating of D600R surfacing electrode and then electrodes were pressed. Deposited efficiency, melting temperature of coating, usability and the hardness and wear resistance of welded metal were measured.The result proves that thinning titanium iron can improve the usability of electrode, enhance the hardness of welded metal, and lower its wear resistance. Thinning rare earth silicon can increase the melting temperature of coating and the hardness and wear resistance of welded metal. The deposited efficiency will increase when putting any fine powder into coating. And the interaction of three fine powders can improve hardness and wear resistance of welded metal. It is find that the performance of electrode is the best, when thinning titanium iron and marble at the same time.