Research On Choosing Material And Abrasion Resistance Of Chain For Suspension Chain Bucket Ship Unloader

Suspension chain bucket ship unloader(SCBSU) is an effectively,continuously,unload ship mechanism which is used for inland waterway harbor . In this test, we search for a available way to improve the abrasion resistance property of chain for SCBSU by choosing material and doing some heat-treatment.The chains are the main parts that may easily wear out. They are working in an open surrounding without lubrication and there is much mine dust around them. The main failure form of them is abrasion. Especially the short lifespan of the outer-sleeve and dowel result in the shutdown that makes a great deal loss.This test analyzes the serving condition, failure from of the chain, refers to the internal and international reference and all-round considers technologic property and economy of steel. We base on the 40Cr and improve the amount of carbon , chose 55SiMnVB,60Si2Mn and 65Mn as experimental materials, through heat-treatment technology and the comparative experiment of abrasion , we prove that the durability of 55SiMnVB and 60Si2Mn is distinctly superior to the 40Cr . Thus, we adopt 55SiMnVB and 60Si2Mn for the chain of SCBSU .Form the heat-treatment and abrasion experiment, we further prove that 55SiMnVB as outer-sleeve and dowel material, has some effect to abrasion resistance property. The experiment shows that 55SiMnVB heated 880℃, time temperature cooling at 285℃, can gain the structure (50%M + 50%B) which has the pretty durability, meanwhile get not only the strength but also the ductility better.Using optics metallographic microscope and scan electric microscope (SEM), we observed the top layer and hypo-surface of the 55SiMnVB experimental sample, and analyzed the principle of its durability, then discover that ductile distortion principle hold the leading position during abrasion, meanwhile it has micro-cutting function. Using optics metallographic microscope we get ductile distortion in hypo-surface and owing to the decarbonization leading the re-crystallization phenomenon in surface of sample.Chain for SCBSU made by the Huludao Sanwei Ship- mechanism Factory and Bohai Ship-building Vocation College has a good practical affect. Especially the main details, such as outer-sleeve and dowel, of with durability and using lifespan can be improved distinctly.