国产熟女一区二区三区五月婷,中文亚洲av片不卡在线观看,亚洲精品国产suv一区88,亚洲成av人片在线观看www

Welcome to the official website of Dalian wanderrui Import & Export Co., Ltd!

National consultation hotline

0411-66886100

Your current location : home >> News >> Technical center

Using low pressure casting method can not solve the shrinkage defects of castings

Date of issue:2018-04-20 00:00 Source:http://hychibao.com Click:

Rockwell hardness tester is also commonly used for hardness test of cast iron. For the workpiece with fine grain, if there is not enough area for Brinell hardness test, Rockwell hardness test can also be carried out. For pearlitic malleable iron, chilled iron and steel castings, HRB or HRC scale can be used. If the material is uneven, several readings shall be measured and the average value shall be taken.


Dalian castings usually have uneven structure, large grains and more carbon, silicon and other impurities than steel. The hardness varies in different small areas or at different points. However, the indenter size of the Brinell hardness tester is large and the indentation area is large, which can measure the average hardness of the material within a certain range. Therefore, the Brinell hardness tester has higher testing accuracy and less dispersion of the hardness value, and the measured hardness value can better represent the actual condition of the workpiece hardness. Therefore, Brinell hardness tester is widely used in foundry industry.


From the origin of metal casting to now, both at home and abroad, people in gravity casting to a large extent use molten metal, then pour it into the pre cast mold, with the help of self weight feeding and solidification of the metal, so as to obtain the designed castings. Whether ferrous metals or non-ferrous metals, people still use the above methods to produce castings.


Later, due to the hard exploration of casting work, many casting theories, viewpoints and methods were published. Now the most popular casting theories are "sequential solidification", "simultaneous solidification", as well as "directional" and "diffusion solidification". Therefore, almost all foundry workers use these theories to guide teaching, design and produce their own castings.


In order to realize natural feeding, we must have the process measures that can realize "sequential solidification" in our casting process system. Many people intuitively think that the shrinkage cavity and porosity defects of castings can be solved by low-pressure casting, but this is not the case. The use of low-pressure casting process does not solve the shrinkage cavity and porosity defects of castings. If the low-pressure casting process system is not equipped with feeding process measures, then the blanks produced by this low-pressure casting method may also have shrinkage cavity and porosity defects.



Relevant labels:

Recent browsing:

Related products:

Related news:

大連船用零部件

Scan and pay attention to us

National consultation hotline:

0411-66886100

Q Q:52410155

Mailbox:wangdewen@wanderui.com

          zhuxingguang@wanderui.com

Address:No. 730, Southwest Road, Shahekou District, Dalian

Dalian wanderrui Import & Export Co., Ltd版權(quán)所有  Specializing in大連鑄造件,大連船用零部件,大連電機殼  遼ICP備16001801號
Powered by Clouds platform  Technical Support:聯(lián)企時代
Main business area: 大連 沈陽 鞍山 撫順 本溪 丹東 錦州 營口 阜新 遼陽
Online Service
share
久久亚洲精品成人无码网站夜色| 性高朝久久久久久久3小时| 少妇爱做高清免费视频| 国产女人AAA级久久久级| 中文字幕日韩精品有码视频| 亚洲成AV人影片在线观看| 亚洲国产精品无码第一区二区三区| 欧美35页视频在线观看| 精品一卡二卡四卡日产乱码| 亚洲欧洲AV无码专区| a级黑人大硬长爽猛出猛进| 久久综合精品无码AV一区二区三区| 夜夜添无码一区二区三区| 亚洲AV无码之国产精品| 欧美激情一区二区三区在线| 伊人久久精品无码麻豆一区| 欧美成人一区二区三区在线视频| 熟妇无码乱子成人精品| 国产精品无码永久免费888| 中文字幕一区二区三区久久网站 | 无码免费一区二区三区| 人妻厨房出轨上司HD院线| 国产综合色产在线精品| 国模少妇一区二区三区咪咕| 午夜视频久久久久一区| 亚洲人成电影网站色www| 午夜精品久久久久久| 久无码久无码av无码| free性玩弄少妇hd| 996久久国产精品线观看| 亚洲精品国产成人AV| 日韩精品久久无码中文字幕| 老司机午夜精品99久久免费| 日韩gay小鲜肉啪啪18禁| 亚洲av无码国产精品久久不卡| jzzijzzij亚洲乱熟无码| 狠狠色噜噜狠狠狠狠av不卡| 日本免费一本一二区三区| 老司机永久免费视频网站| 亚洲亚洲中文字幕无线码| 国产在线精品一区在线观看|