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The sealing principle and characteristics of flange

Sealing of flat-welded flanges has always been a hot issue related to the production cost or economic benefit of enterprises. However, the main design disadvantage of flat-welded flanges is that they are not leakproof. This is a design flaw: the connection is dynamic, and periodic loads, such as ... Read More

What should be noted in the examination of die forgings before heat treatment?

The inspection before solution heat treatment is a pre-inspection procedure to check the finished product's surface quality and dimensions according to the technical conditions, die forging drawing and process card after the forging forming process is finished. Specific inspection should pay atte... Read More

Congratulations on Resumption of Work

Congratulations on Resumption of Work Dear new and old customers and friends, Happy New Year. After a happy Spring Festival holiday, Lihuang Group (DHDZ)started normal work on February 18th. All the work has been well organized and carried out as usual. Read More

DHDZ forging 2020 year-end review meeting and 2021 welcome party for freshmen

2020 is an extraordinary year, the outbreak of the epidemic, the whole country is difficult, big state organs and some enterprises, small to every employee and ordinary people, all bear a huge test. At 15:00 on January 29, 2021, DHDZ forging organized the 2020 annual year-end summary meeting and... Read More

How to find the processing difficulties of stainless steel flange

First of all, before choosing the drill bit, take a look at the difficulties in stainless steel flange processing. Find out the difficulty can be very accurate, very fast to find the use of the drill. What are the difficulties in stainless steel flange processing? Sticky knife: stainless steel pr... Read More

What is the process of forging?

1. Isothermal forging is to keep the temperature of billet constant during the whole forming process. Isothermal forging is used to take advantage of the high plasticity of certain metals at constant temperature or to obtain specific structures and properties. Isothermal forging requires the mold... Read More

The main disadvantages of water as a quenching cooling medium for forgings ？

1) in the austenite isothermal transformation diagram of the typical area, that is, about 500-600℃, water in the steam film stage, the cooling rate is not fast enough, often cause uneven cooling and insufficient cooling speed forgings and the formation of the "soft point".In the martensite transf... Read More

What kind of bolt connection does stainless steel flange use?

Customers often ask: stainless steel flange connection whether to choose stainless steel bolts? Now I will write what I have learned to share with you: Material has nothing to do with the material of flange bolts, according to the European system HG20613-97 "steel pipe flange with fasteners (the... Read More

How to use welding flange correctly

Flanges With the rapid development of domestic foreign minister pipeline construction, pipeline pressure test has become an essential important link, before and after the pressure test, must pass the ball sweep line for each section of the pipeline, the number of times is generally 4~5. Especiall... Read More

Applications of hardenability and hardenability of forgings

Hardenability and hardenability are the performance indexes that characterize the quenching ability of forgings, and they are also the important basis for selecting and using materials.Hardenability is the maximum hardness that a forging can achieve under ideal conditions.The main factor determin... Read More

The way to improve the plasticity of forging and reduce the deformation resistance

In order to facilitate the flow forming of metal billet, reduce the deformation resistance and save equipment energy, the following methods are generally adopted in forging process: 1) Grasp the material characteristics of forgings, and select a reasonable deformation temperature, velocity and de... Read More

Flange standard

Flange standard: National standard GB/T9115-2000, Ministry of Machinery STANDARD JB82-94, Ministry of Chemical Industry standard HG20595-97HG20617-97, Ministry of Electric Power standard GD0508 ~ 0509, American standard ASME/ANSI B16.5, Japanese standard JIS/KS(5K, 10K, 16K, 20K), German standard... Read More
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