电铲的环轨表面剥离原因分析  

Failure Analysis of Spalling Ring Rail Working Surface of Power Shovel

作　　者：陈联满[1] 张明如[1] 王越[1] 杨丽珠[1] 徐道元[1] 

机构地区：[1]马鞍山钢铁股份有限公司,马鞍山243000

出　　处：《失效分析与预防》2006年第1期57-60,64,共5页Failure Analysis and Prevention

摘　　要：4m^3电铲的环轨工作表面发生早期剥离,本文对剥离环轨的化学成分、显微组织及断口特征进行了分析。分析结果表明：环轨的剥离断口形貌为疲劳断裂,其工作面淬硬层深度不足2mm,低于图纸技术要求的4mm～5mm。淬硬层以外区域的布氏硬度为200HB～204HB,也低于技术条件要求。环轨的基体组织为粗大不均匀的回火索氏体,铁索体呈网状、针状分布,属于热处理的缺陷组织。环轨的周向组织呈严重的带状分布,材料中的非金属夹杂物含量比较多。环轨的早期失效属于交变接触应力作用下的疲劳剥离,是由环轨的热处理组织缺陷和材料中含有较多非金属夹杂物等因素的综合作用引起的。Spelling at early stage was occurred on ring rail working surface of power shovel. In order to find out the reason, the chemical compositions, macro and micro analysis on the fracture and structure of the ring raft were carried out. The analysis result of impection was as follow： the morphology of ring rail＇ s spelling fracture is fatigue failure. The depth of quench hard layer of the working range was less than 2mm, which was lower than the drawing specification requirement of 4mm - 5mm. Hardness of the outside area of quench hard layer was 200HB - 204HB, which was also lower than technological requirement. Matrix structure of ring rail was crass and heterogeneous tempered sorbite. The ferrite distributed as the form of network and needle. They belonged to the defect structure of heat treatment. The circumferential direction structure of ring rail distributed seriously as banding form and there were many non-metallic inclusions in the material. The above-mentioned results indicated that the early failure of ring rail was fatigue spallling under the action of alternation contact stress. It was caused by heat treatment structure defects of the ring rail and the more non-metallic inclusions in the material, etc.

关 键 词：环轨 剥离 淬硬层 非金属夹杂物 

分 类 号：TG623.8[金属学及工艺—金属切削加工及机床]