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Ductile iron crankshaft rare earth catalytic gas nitrocarburizing


Changed the composition and structure of the diffusion layer. Juxian agricultural machinery plant in the SDIi00 crankshaft, the rare earth catalytic gas nitrocarburizing, shorten the process time 33,herve leger sale, the surface hardness and microstructure of the standard requirements; Yiyuan diesel engine plant installed by the trial,######## oakley sunglasses, the working life than the original gas nitrocarburizing improved handling of ductile iron crankshaft 10. 2CO ~ CO2 + [c] ZNH {a 2 [N] +3 H2H + cO bucket [C] + H: O In addition, we also believe that: rare earth surface itself may also be adsorbed, as a surface between the ; 3 ductile iron rare earth catalytic mechanism nitrocarburising 4 Conclusion Although many of the rare earth catalytic chemical heat penetration data are reminders that the rare earth elements in the seepage and also participate in permeation,ed hardy uk, the rare earth elements can penetrate the surface. But on the rare earth catalysts nitrocarburizing iron ball through spectrum analysis of multiple samples. Has failed to find a ce, La and other rare earth elements exist. Therefore, we believe in nitrocarburizing process, rare earth elements only act as a catalyst. That plus Liuqing Bin (1) rare-earth iron crankshaft of the ball gas nitrocarburizing a clear reminder infiltration role, permeation time can be shortened by about 30. (2) rare-earth reminder, after infiltration, nodular iron crankshaft nitrided layer hardness distribution changes, a slight decrease in surface hardness, hardness of the diffusion layer was significantly increased, the hardness tends to gentle gradient, thus prolonging the service life of the crankshaft. Received: September 15, 1997 fire south experimental study of wear layer. . Research Abstract small bream steel laser hardening layer 40CrNiMoA organization, wear resistance and wear mechanisms. The results showed that: laser quenching has good resistance to Pa, a long period of large diesel engine piston temperature, pressure and corrosive atmosphere of work. So. Piston wear, especially the first ring groove wear, determines the life of the piston. How to improve the wear resistance of the piston ring groove has been the people's attention and in-depth study of the smell problem, strain hardening can not only improve the surface properties of materials and processing methods are difficult to meet the general technical requirements 0]. Therefore, this laser 40CrNiMoA steel and wear resistance after quenching the organization are analyzed and discussed. 2 Test methods Test Large selection of materials commonly used in diesel engine piston crown material 40CrNiMoA quenched and tempered steel. Its chemical composition (wt) is: 0.38c.0.72Cr.1.26Ni.0 + l88Mo, 0.228Si.0.597Mn.0.0148P, 0 .0 ll9s. Sample size l2 × 22 × 44 (ram), the surface roughness Ral_6 original heat treatment: 850 ℃ oil quenched, 520 ℃ indiscriminately fire. specimens cleaned by acetone painted black organic coating, the choice of HGL89 cross-flow type 2kW CO laser heating, laser surface treatment process parameters: irradiation power] ~ 1.4kW, spot diameter of 5mm, a scan speed of 20 ~ 40mm / s. with D / max_rf anode rotating anode x-ray diffraction phase analysis of hardened layer, with S-550 scanning electron microscope analysis of hardened layer structure and surface morphology of wear. Shimazu micro hardness tester with a hardened layer hardness measured in MM200-type wear testing machine and wear test, carbide grinding wheel material YG6 Dimensions 40 × 10ram. load 98.1N, wheel speed 200r/min, wear time 2h. material wear resistance was assessed using weighing method, that is, before grinding wear a heavy - weight after grinding 3 Results and discussion 3.1 hardness analysis of x-ray phase and microstructure analysis showed that: 40CrNiMoA quenched and tempered steel hardened layer formed by the martensite and residual austenite Figure l is the laser hardened layer microstructure SEM photographs in the case of surface melting does not occur next. test block surface transformation hardening by laser treatment, the surface hardness up to HV750 about hardening depth of 0.5ram more than 2 for the laser hardening after quenching and high-frequency hardened layer hardness gradient shows,knock off oakleys, laser hardening layer hardness than the high-frequency quenching increased nearly 100HV The reason is that the laser rapid heating and subsequent rapid cooling process, the austenite grain has been refined; martensite in carbon and a large number of elements dissolved in box sets of static distortion caused by enhanced; retained austenite in carbon and the solid solution strengthening alloy elements combined result of factors such as level 3.2 Quench wear male, 28 years old - Dr. Fan power Bing. Post-doctoral More articles related to topics：


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