Casting historic application. Ancient people used to make castings and some life appliances. In modern times, mainly used for casting machine parts rough ports bollard, some precision castings, can also be used directly as machine parts. Casting mechanical products occupy a large proportion, such as tractors dock bollard manufacturers, casting weight of about 50 to 70% by weight of the machine, agricultural machinery accounted for 40 to 70 percent, machine tools, internal combustion engines, etc. up to 70 ~ 90%. All kinds of castings, casting machinery most varieties bollard dock equipment, the most complex shapes, the amount is also the largest, accounting for about 60% of total production of castings. Followed by the ingot mold and metallurgical engineering pipeline, as well as some of the tools of life. Casting is also closely related to daily life. For example, often use the door handles, locks, radiators, down the water pipes, pots, gas hob, iron, etc., are casting. Casting defects: cold resisting grain Other names: Splice (butt), waterlines. Characteristics: a relatively low temperature metal flow butted to each other but not fusing gap occurs, irregular linear, there are two kinds of penetration and do not penetrate, the trend of development under the action of external forces. Reason: a molten metal pouring temperature is low or the mold temperature is low. 2, alloy composition does not meet the standards, poor mobility. 3, sub-unit filled with liquid metal, fusion is bad. 4, gate unreasonable process is too long. 5, filling speed is low or poor venting. 6, lower than the pressure. Bollard dock pier bollard equipment _ _ Chen Hua Chen machinery provided by Qingdao China Machinery Equipment Co. Qingdao Hua Chen Machinery Co., Ltd. (www.qdchenhua.com) strong, credible, in Qingdao, Shandong CNC machine tool industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Chen Hua machinery and you hand into the brilliant, for a better future!