Plasma nitriding technology application in the crankshaft production ( 2)

1. Cleaning process to be processed parts should be clean before furnace charging parts surface clean and oil free, at present the main cleaning methods mainly have the following ways: (1), high temperature steam add detergent washing and then add the high temperature steam bleaching washing; (2), automatic washing machine cleaning; (3), gas scrubbing. The third way is in production conditions do not have the workaround, applies only to small cleaning. 2. Nitriding process of ion nitriding process parameters is commonly: average temperature of 100 ℃ / hour; Between heat preservation temperature: 540 ~ 580 ℃. Holding time: 6 ~ 8 hours. Ion soft nitriding process parameters is commonly: the average temperature 100 ℃ / hour; Between heat preservation temperature: 540 ~ 570 ℃. Holding time: 3 ~ 4 hours. Third, the quality control in the process of crankshaft nitride 1. Cleaning cleaning is good or bad will directly affect the quality of the crankshaft treatment and extend the processing cycle. If the dirty surface of the crankshaft, arc duration will be greatly extended, a factory in the past, due to the time of crankshaft cleaning not clean bowl extended to more than 12 hours. After processing of crankshaft many adhered on the surface of carbon black, affect the product appearance and affect the quality of the product. Cleaning process after the improvement, the arc time shorten, processing quality is greatly improved. According to our diesel engine oil pump in dongfeng motor system pump factory processing channel plate on the experience, the thickness of surface cleaning easy to form a continuous relatively homogeneous compound layer, the opposite is not easy to form a continuous and thickness of the compound layer. And compounds in ion nitriding layer on the hardness, wear resistance and fatigue resistance performance has great contribution. We think it unclean is mainly formed by the surface of carbon black with free carbon in the form of affecting parts surface activation, hindered the nitriding. 2. Ion nitriding equipment compared to the traditional nitriding process has many advantages, but because of the particularity of its vacuum discharge, and has brought a great evils, this is the non-uniformity of temperature distribution in furnace parts. This shape on the one hand, because of parts surface will affect the surface current density distribution, save electricity, save material, small energy consumption; (4) no environmental pollution and so on. After ion nitriding parts, the surface hardness is higher, fatigue resistance and antifriction performance are improved. Four, ion nitriding technology present situation and the processing of the crankshaft is similar to other nitriding parts, crankshaft of ion nitriding process generally go through arc, heating, insulation, cooling and other four stages, including the furnace charging, roughly 18 hours. Different manufacturers on the ion nitriding process is slightly different. In terms of deformation, as long as the aging treatment of good ( About 2 ~ 4 hours) , uniform temperature can ensure the deformation is small, weifang diesel engine factory of nitride crankshaft axial runout is generally not more than three. About soft nitriding, dalian diesel engine factory adopted the practice of ammonia and acetone, heat preservation time is 5 hours according to reflect ion soft nitriding is slightly bigger than nitriding deformation, according to our channel plate in dongfeng automobile factory processing experience, as well as driving ring using ammonia and propane gas and ion nitriding treatment, process easier to control. I recently developed by the high-power pulse power, average power has been more than 120 a, can fully meet the requirements of 150 kw to nitriding furnace. A new pulse power supply tested for its stability power supply reliability is better than the past. Due to save the current limiting resistor, that alone can power saving is about 20%, and other characteristics of pulse power supply, under certain conditions, power saving up to 50%. Using pulse power, the arc time, oil hole is not blocked the auxiliary furnace charging time, power operation is simple, easy to control. Five, the conclusion on the crankshaft products adopts the ion nitriding process is advanced in technology, the quality is superior to the traditional gas nitriding nitride, at present some problems found in the equipment in use process is easy to be explained and solved, and the successful development of pulse generator and the auxiliary furnace charging time, arc cleaning time, save energy, many advantages of ion nitriding process will be more and more know the crankshaft manufacturer. I stands ready to work together with the crankshaft manufacturer, improving equipment and process, in order to improve the quality of the products we should do our efforts of crankshaft.