Manufacturing method for 195 diesel engine flywheel casting

Abstract

The invention relates to a manufacturing method for a 195 diesel engine flywheel casting in terms of weight percentage. The method is characterized by comprising the steps of: 1) burdening, 2) manufacturing, 3) jetting of scrap steel and ferromanganese in front of a furnace, 4) inoculation treatment, and 5) second inoculation and pouring. By controlling the Si / C value of molten iron, jetting manganese into a ladle in front of the furnace to adjust the [Mn-Si] value, and jetting scrap steel into the ladle in front of the furnace to improve supercooling so as to enhance the inoculation effect, and adopting a silicon barium alloy lander jetting technique for first inoculation and ferrosilicon alloy secondary inoculation in a pouring ladle, the high quality 195 diesel engine flywheel casting can be manufactured under the conditions of a carbon equivalent of 3.9-4.05% and no alloying. The content of pearlite in the casting microstructure reaches 88%, the tensile strength sigma b is 259-266Mpa, and the hardness HB is 185-200.

Description

Technical field [0001] The invention relates to the field of casting processing, in particular to a method for controlling the Si / C value of molten iron, [Mn-Si] difference, and flushing scrap steel and ferromanganese in the molten iron ladle in front of the furnace, and using barium silicon inoculant to inoculate and ferrosilicon at one time. The inoculant secondary inoculation method is combined to produce high-strength 195 diesel flywheel castings. Background technique [0002] Because high-strength HT250 cast iron has good vibration damping performance characteristics, and also has certain strength performance indicators, it is widely used in the machine tool and diesel engine industries to manufacture box and support structural parts, such as the manufacture of diesel engine flywheels and engines Cylinder block, engine cylinder head, machine bed, guide rail and other parts. [0003] At present, when preparing high-strength flywheel castings of HT250, due to the relatively lar...

AI Technical Summary

Problems solved by technology

[0003] At present, when preparing HT250 high-strength flywheel castings, due to the relatively large thickness of the flywheel castings, the casting structure is low, the graphite size is large, and the shape is poor, and the performance of the castings is difficult to meet the HT250 index requirements.

Therefore, in order to stabilize and improve the performance index of castings, when manufacturing castings, alloying elements such as copper, chromium, and molybdenum are often added to molten iron alone or at the same time, which increases the manufacturing cost of castings.