In terms of detection methods, GB7233-09 focuses on the near-field area of ultrasonic flaw detection, and adds a near-field resolution probe. The so-called near-field area is the area where a series of maximum and minimum values of sound pressure appear near the wave source due to wave interference. It...
Casting is a traditional and ancient production technology with a history of more than 4000 years. China is a big country in foundry production. According to relevant reports, China casting production in 2017 has reached 28 million tons, ranking first in the world. With the gradual transfer of manufacturing...
Domestic research on low temperature impact toughness of nodular cast iron started late, but it has developed rapidly in recent years. Before, the domestic wind power generation technology was not perfect, and the operation cost of wind power was high. Although it was widely valued, there were few substantive...
In addition to the study of chemical composition, heat treatment process and metallographic structure, many studies have been carried out on trace elements in nodular cast iron in China. Xu Feng and others from Qiqihar No.1 Machine Tool Plant studied the metallurgical behavior of trace chain and antimony in...
It plays an important role in the development of foundry products. According to the statistical data of a certain year in Table 1, at present, the casting exporting countries in the world are mainly China, the United States, Russia and Japan; It can be seen from table 2 that...
China has entered the ranks of the world’s largest foundry countries, and the production scale and types of castings of the foundry industry have entered the forefront of the world. However, China’s foundry industry still has a high scrap rate. The scrap rate of ordinary iron castings in China...
Large steel castings have large size and long production cycle. They are generally produced in small batch or even single piece. Therefore, the traditional trial and error method is no longer suitable for the production of large steel castings, otherwise it will bring huge losses to enterprises. The numerical...
In recent years, the domestic pump and valve casting industry has developed rapidly, but there are still many problems in its development. Due to the long-term price war in the domestic pump and valve industry, the pump and valve industry has been hovering at the middle and low level...
Large castings have long production cycle and complex processes. Generally, they have to go through many processes. Reasonable setting of various processes in the casting process is the key factor to determine the final successful casting. 1. Molding process Most large castings are shaped in the pit. The sand...
Compared with industrial developed countries, there is a big gap in the production of large steel castings in China in terms of product variety, process level, quality grade and manufacturing equipment. In the large-scale nuclear power equipment, the main pump, nuclear power turbine cylinder and other large steel castings...