Large Forging Prices: Extreme Manufacturing of Large Forgings_Jiangyin Hengye Forging Co., Ltd-Mechanical hardware-Cartridge

NEWS

Jiangyin Hengye Forging Co., Ltd

company news

Industry News

common problem

Large Forging Prices: Extreme Manufacturing of Large Forgings

Release time:

2022-04-08

Large Forging Prices: Extreme Manufacturing of Large Forgings

Large forging prices: The traditional manufacturing method of large forgings is to use large steel ingots for billeting and free forging. However, with the continuous development of major equipment, the requirements for large forgings are getting higher and higher, not only the specifications and cross-sections are getting larger and larger, but the internal quality is also improving, and the traditional manufacturing methods have been difficult to meet the requirements. In order to meet the needs of high-end equipment and achieve the goal of taking into account the shape and quality of large forgings, it is urgent to reform the manufacturing method. Therefore, extreme manufacturing methods such as homogeneous billet making, integrated manufacturing and die forging, represented by the improvement of traditional ingot manufacturing technology and the development of new additive billet making technology, have emerged as the times require. Large forging price

Large forgings are the basic components of electric power, metallurgy, petrochemical, shipbuilding, mining, aerospace, military and other equipment (Figure 1). They have strong economic driving force and wide coverage, and are an indispensable link in the equipment manufacturing industry chain.

Price of large forgings: The traditional manufacturing method of large forgings is free forging. In order to reverse the passive situation of low material utilization rate, high cost and unstable quality of large forgings, it is necessary to innovate ideas, challenge the "impossible", and transform and upgrade large forgings. Through homogenization, integration, and forging, the goal of ultimate manufacturing can be achieved. Large forging price

Large Forging Prices: Homogenization and Billeting

The quality of large forgings is mainly manifested in purity, uniformity and compactness. To improve the quality of large forgings, reduce manufacturing costs, and achieve ultimate manufacturing, we must start with the "three properties" of forgings. The relationship between different hot working procedures and forging "three properties" is shown in Table 1.

It can be seen from Table 1 that in the hot working process of large forgings, ingot/blank making is the key and important link that affects the three properties of forgings. Therefore, domestic and foreign forging suppliers pay more and more attention to the preparation of forging blanks. In order to obtain a homogenized billet, in addition to the integration and innovation of the traditional billet making process (smelting, ingot casting, billet opening), various methods of charging billet making are also eager to try.

Preparation of large and very large ingots

In order to improve the uniformity and purity of large and super-large steel ingots, China First Heavy Industries Co., Ltd. has invented a series of smelting and ingot casting technologies

Low-silicon aluminum-controlled steel smelting technology.

In order to reduce inclusions and obtain essentially fine-grained steel, the low-silicon aluminum-controlled steel manufacturing technology was invented. It not only improves the purity of molten steel and obtains essentially fine-grained steel, but also effectively controls the composition segregation of super-large steel ingots and reduces the inclusion and gas content in the steel ingot. By smelting and pouring low-silicon aluminum-controlled steel, high-quality forgings with uniform composition and few inclusions are produced. Large forging price

Protective downpour.

1) New tundish.

In order to reduce the involvement of steel slag in the ingot mold during the ingot casting process, a new type of tundish with a retaining wall and a dam was invented by learning from the experience of continuous casting of "retaining walls" and "damping dams" in the metallurgical industry. Numerical simulation and engineering practice show that, compared with the traditional round tundish, the inclusion content of the super-large steel ingot cast by the new tundish is greatly reduced. 2) Long shroud protection pouring. Large forging price

Air entrained in the pouring process is an important cause of secondary oxidation of molten steel. The secondary oxidation of molten steel will not only form harmful oxide inclusions and lead to scrapped forgings, but also increase the gas (H, O, N) content in the ingot. High gas content is one of the main causes of defects in oversized forgings. In order to avoid the secondary oxidation of molten steel, based on the experience of the metallurgical industry, a long shroud protection pouring technology was developed, which effectively avoided the secondary oxidation of molten steel.

3) Secondary pouring.

It is the inevitable result of molten steel segregation crystallization and ingot solidification. The larger the ingot, the more serious the segregation, shrinkage and other defects. When Heavy Machinery Co., Ltd. was developing backup rolls with a 459t steel ingot with an average C content of 0.62%, the roll body broke near the riser. By analyzing the macro-morphology of the fractured part, it was found that the secondary shrinkage was serious, and the C content in the lower part of the riser was as high as 1.16%, which was nearly twice the standard value. In order to solve this problem, we invented the secondary ingot casting technology to reduce the C content in the lower part of the riser to about 0.8%, and successfully produced 5m and 5.5m super-large ingots for backup rolls.