Analysis of casting defects of bolts

The occurrence of casting defects in the cylinder head bolt holes is directly related to the design of the gating system and the ability of the molten iron itself to graphitize and expand. This is because when the carbon equivalent is low, the precipitated graphite is limited, and the amount of graphitization expansion is small; and the amount of shrinkage of the molten iron equivalent and the pouring temperature is determined.

The solid cylinder of the cylinder head bolt hole is 100mm*150mm, and its peripheral wall thickness is only 18mm. It is impossible to obtain the liquid shrinkage from the riser provided at the top of the body. It can only be used from the inside during the pouring process. The gate is obtained. The inner gate of the pouring system of the original body is introduced from the vicinity of the cylinder head bolt hole, so that the hot joint portion is always in the flushing of high-temperature molten iron throughout the pouring process, and the temperature of the portion is high after the pouring, and the liquid shrinkage is higher. It is large and does not receive any shrinkage, causing shrinkage and shrinkage defects in the part. The cylinder head bolt hole close to the air chamber is relatively far away from the inner runner, the temperature during the casting process is continuously reduced, the volume shrinks and the liquid metal can be replenished from the inner runner.

Based on the above reasons, the following measures were taken:

(1) Smelting process: increase the carbon equivalent of molten iron and strengthen the inoculation treatment. When the carbon equivalent is about 4.65, the spheroidization level is 12, and the graphite size is 56, the molten iron has the strongest graphitization expansion capacity, which is beneficial to reduce the shrinkage and shrinkage of the cylinder head bolt holes.

(2) Modeling process: change the runner and the gate to the bottom of the cam cavity, so that the gate is away from the cylinder head bolt hole, so that the part can get the full supply of hot iron water without causing the The part is overheated. At the same time, an outer cold iron is arranged at the hole of the cylinder head bolt. In this part, strong sequential solidification is caused, which is more conducive to the feeding of the part of the inner runner, thereby achieving the purpose of eliminating casting defects such as shrinkage and shrinkage in these parts.

Drainboard Sink

Drainboard sinks are sinks that have an attached drainboard usually on one side but sometimes on both sides. This drainboard is grooved and slightly angled down so that water drains directly into the sink while dishes are resting on it. It is a kitchen accessory that helps you to dry your dishes.

Drainboard Sink,Cast Iron Sink With Drainboard,Washboard Sink,Double Bowl Sink With Drainboard

JIANGMEN MEIAO KITCHEN AND BATH CO.,LTD , https://www.jmmeiaogroup.com