Selection of bucket tooth wear-resistant material
For many years; The investigator has carried out a large amount of explorations in the selection of bucket tooth wear-resistant material; Most work are the basis with high mangaenese steel, improve the performance of high mangaenese steel through adding some alloys, and bucket tooth material commonly used has high mangaenese steel bucket tooth and low carbon martensite Complex Alloy Steel bucket tooth.Wherein the high mangaenese steel bucket tooth comprises common high mangaenese steel bucket tooth, modified high manganese steel bucket tooth and Manganal bucket tooth.
1) common high mangaenese steel bucket tooth: high mangaenese steel (ZGMn13) is used as bucket tooth material earlier.The advantage of the bucket tooth of processing with this material be when receiving HI high impact work hardening capacity strong (in the use of mine, the bucket tooth surface hardness can reach HB400～HB500).The high mangaenese steel bucket tooth is fit to excavate the high firmness material, is not suitable for excavating softer material (coal, earth etc.), because of softer material can not make it abundant work hardening, so abrasion resistance is relatively poor.Units such as Anshan iron and steel plant mine study-a institute and Shoudu Iron and Steel Co carry out setting treatment with the explosion hardening method to the high mangaenese steel bucket tooth, and through examination, the life-span can improve 35～40%.
2) modified high manganese steel bucket tooth: for improving ys, toughness and the wear resistance of high mangaenese steel bucket tooth, the AMSCO company of the U.S. has adopted common high mangaenese steel to add Cr, Mo with ESCO company or steel alloy has been carried out disperse handle the bucket tooth of making use under the suitable different working conditions.A kind of excavator bucket teeth that uses on the Russia stone quarry has also adopted modified high manganese steel, wherein contains V, Ti composition, and the bucket tooth life-span improves 50%.The many producers of the production industry of China’s excavator are once at 1m 3And 4m 3Carried out the Combined Trials of bucket tooth material on the power shovel.Through in high mangaenese steel, adding trace elements such as Mo, Cr, V, Ti, RE, adjust Chemical Composition, all there is raising in various degree in the life-span.
3) Manganal bucket tooth: some tractor plants of the U.S. develop and contain Ni high mangaenese steel (contain 1.5～2.0%Ni), improve casting technique simultaneously, the bucket tooth life-span has clearly improves.
4) low carbon martensite Complex Alloy Steel bucket tooth
Under the medium impact operating mode, high mangaenese steel toughness is had a surplus and wear resistance is relatively poor, for this reason, has developed a series of low alloy steel both at home and abroad, is used to make bucket tooth.
In order to guarantee that bucket tooth has enough toughness; The low alloy steel that is used for bucket tooth at present mostly is low-carbon type; Its carbon content is main alloy element generally below 0.32% with Cr, Ni, Mo, Si, Mn, B etc., improves wear resistance with hardening capacity or the formation carbide that improves steel.Representational alloy system is Mn-Cr, Cr-Mo, Ni-Cr-Mo, Si-Mn-Cr-Mo etc.
Low-carbon and low-alloy martensitic steel carbon content is generally 0.2～0.3%, is no more than 0.32%.Because carbon content is low,, be characterized in that toughness is high so can shrend obtain the lath martensite tissue; Good weldability; Have higher hardness and wear resistance through low-temperaturetempering, can be used under the higher ballistic situation, this type steel of produced in usa has 90% to be used to make bucket tooth at present.The exploitation of the AMSCO company of the U.S. contain Ni-Cr-Mo low carbon martensite Complex Alloy Steel, be a kind of HS and excellent abrasive resistance bonded material, through different heat treatment, can enlarge the scope of application of its mechanical property and hardness.The 280-B type excavator bucket crown of U.S.’s surface mines use at present etc. has adopted this material.The dipper capacity of the Marion manufactured of the U.S. is 8m 3Bucket tooth also use this steel.