The Study Of The Preparation Technology Of Horniness Surface Layer On Piston Ring

This article in view of the piston ring working in bad condition, the resistance to wear and the bear to erode request high, and the dosage is greatness, the batch is bigness, requests a better efficiency, according to the principle of "cost low, the performance is good", namely obtains the best practical craft plan through the experiment, then analyzes its operational performance and the microscopic organization. Begins from the superficial alloy basic principle, inspect influence factors to 40 steel surfaces WC the high carbon Cr. In the choice of material aspect, carries on aspect the and so on performance, price to several kind of related materials comparison, finally determined selects ZG40 to take the substrate, WC and the high carbon chrome iron takes the enhancement. This topic experiment approximately divides into following several steps to carry on;First, use "coating" to conduct the research to 40 steel bases surface alloy, through the change experimental parameter such as pouring temperature , cementing agent, bake temperature and so on, obtained the different result; The main process factors influencing the qualities of surface alloying of a piston ring were pouring temperature, and the optimum process parameters were determined that provided a basis for the practical production .Through the test, the best optimum was showed as follow : Using Cr-Fe, FeB alloy powders, WC, Mo and Cu metal powders as raw materials, pouring between 1620℃and 1650℃,coating thin was 2.0 mm to 3.5 mm , the amount of the binder is 3%, and the flux is 3%, keeping temperature at 300℃for 3 h. In this way, the alloy layer with better quality can be obtained and the alloy layer has pearlite matrix and a lot of carbide leading to a high hardness and good wear resistance. The metallographic system of hard alloy cladding material is studied by metallographic microscope and the hardness distribution of composite is measured by sclerometer and themicrostructure and element distribution in cladding material is an analyzed bySEM. The analysis of the component on the casting-infiltration stratum indicates that it has realized the pervasion and the infiltration at the place of the coalescent interphase . There has formed favorable metallurgy coalescent between the hard alloy cladding and the steel.Second,The influence of ion-nitriding process was investigated on microstructure and properties of WC,Cr Hard Alloy Cladding Material Prepared by Casting-infiltration on Casting Surface of piston ring. The metallographic system of hard alloy cladding material is studied by metallographic microscope and the hardness distribution of composite is measured by sclerometer and the microstructure and element distribution in cladding material is an analyzed by SEM. Results showed that some very hard Fe₄N and Fe_2-3N particles(the size was very small) were formed on the surface zone of coating ,whose micro-hardness was increased from 35OHv_0.1 to 85OHv_0.1 after ion-nitriding treatment. The anti—wear of base-steel was improved remarkably by ion-nitriding process. but the micro-hardness of composite coating with WC could not be improved by ion-nitriding process.Finally, use "coating" to carry on the experiment to the piston ring, the test result indicated that, the obtained piston ring superficial alloy quality is good, not obvious casting defect. The micro-hardness and the anti—wear of base-steel was improved remarkably by ion-nitriding process, according to the economic efficiency analysis , this topic research has the practical value.