中空钢ZK55SiMnMo疲劳失效原因分析  

Analysis of Fatigue Failure Causes for ZK55SiMnMo Hollow Steels

作　　者：刘建[1] 杨小军[1] LIU Jian;YANG Xiaojun(Valin Xiangtan Iron and Steel Co.,Ltd.,Xiangtan 411101,China)

机构地区：[1]湖南华菱湘潭钢铁有限公司

出　　处：《金属材料与冶金工程》2019年第5期32-37,共6页Metal Materials and Metallurgy Engineering

摘　　要：ZK55SiMnMo是我国自主研发的钎钢主要品牌钢种,其凿岩使用寿命达到国际先进水平,该钢的综合力学性能优异,具有较好的强韧性匹配,因此成为国内锥体连接钎杆的主要用钢。本文对采用机械钻孔+热轧法生产并经不同正火工艺进行热处理后的中空钢H22锥体连接钎杆抽样进行疲劳台架对比试验,针对疲劳台架试验断裂后的断口分析结果表明:影响钎杆疲劳失效的因素很多;块状复合结构组织比例较大,是导致疲劳寿命异常低的原因;钎杆表面存在一定深度的微缺陷会诱发疲劳裂纹的早期萌生,是导致疲劳失效的直接原因;通过分析结果找出其失效的具体原因,并提出改进建议。ZK55SiMnMo Steel is a major grade of the hollow rock drill steels researched and developed in China and its service life reaches the advanced international level.This steel is provided with excellent comprehensive mechanical properties due to the better combination of strength with toughness,thus,used mainly for making the rock drill rods in cone-to-cylinder junction.In this article,the fatigue bench contrast test was done on the samples from H22 hollow steels produced by mechanical drilling+hot rolling and heat treated with different normalizing procedures.By analyzing the crack tested on fatigue bench,it is resulted that:there are many factors that affect the fatigue failure of drill rods;the more proportions of massive composite microstructures lead to the abnormal shorter fatigue life;the microscopic cracks with some-depth in rock drilling rod surface would induce the inchoation of fatigue cracks,which is the direct cause of fatigue failure.By analyzing the test results,the specific causes of fatigue failure are found out and some suggestions are put forward for improvements.

关 键 词：中空钢 疲劳台架试验 疲劳失效 钎杆 ZK55SiMnMo 

分 类 号：TG115.5[金属学及工艺—物理冶金]