With the rapid development of economy, the domestic demand for large and complex castings in the fields of automobile, aviation, architecture and military industry is increasing day by day, and the lightweight development trend of large castings is becoming more and more obvious, such as large aluminum alloy automobile...
The manufacturing industry of large steel castings is the basic industry of national equipment manufacturing, and its development level is an important symbol to measure a country’s comprehensive national strength. There are more than 30 large steel casting production enterprises in China, most of which are large and medium-sized...
Different from forged steel parts, steel castings for hull structure have low carbon content and good welding performance. Defective parts are allowed to be repaired by welding. The control of the welding repair process is mainly related to the carbon equivalent of the casting material, the area of the...
Hot crack: the crack is an irregular curve, the inner surface is rough and black brown iron oxide. Cold crack: the crack line is relatively straight, and the inner surface of the crack is clean and metallic luster. Fig. 1 JIS rodless anchor claw root arc surface thermal crack...
1. Manifestations of cold crack defects Under the joint action of welding stress and other embrittlement factors, the bonding force of metal atoms in the local area of the welded joint is destroyed to form a new interface. The gap generated by the new interface is a cold crack...
With the continuous development of wind power generation, the manufacturing requirements of wind power equipment are also increasing. Especially in recent years, the development and improvement of land wind farm has turned the attention of many researchers to the development of offshore wind power, which requires wind power manufacturing...
1. Casting process Fig. 1 is the casting process diagram of the main frame and hub of 6 MW wind turbine generator. Both of them are of multi box shape. The main frame machine adopts the inner sprue and the sprue, which are three sets of independent bottom pouring...
Through the calculation of niyama function value, the cniyama value at point 4 far away from the casting riser and end chilling zone is 1.05, which is less than the 1.1 critical value of large steel castings. Therefore, shrinkage cavity and porosity casting defects will occur in the area...
The pouring test was carried out on the improved process of steel castings (using two heating risers for liquid metal feeding, adding cold iron chilling at the end of the steel castings away from the riser, and adding subsidies at the root of the riser). The flaw detection treatment...
Figure (a) shows the beam casting of the crusher (the right side of the casting is the cutting part). The material is zg275-485 and the mass is 30 t. The wall thickness of the casting is thick and the solidification time is long. It is easy to form shrinkage...