The detailed deformation mechanism and its microstructural modifications of white cast iron grinding balls used in comminution have been investigated using transmission electron microscopy (TEM) and XRD. De-shaping is the primary mode of ball consumption, and fracture of balls is a relatively uncommon failure mode. Deshaping is the manifestation of abrasive wear caused during the operation, and abrasive wear is accompanied by microstructural changes. Micro-cutting is the foremost mechanism. The original microstructure of the matrix of unused grinding balls was observed to have twinned martensite with ω phase with an orientation relation of M-(1\(\bar{2}\)1)//T-(\(\bar{1}2\bar{1}\)) and {\(\bar{1}\bar{1}3\)}M//{11\(\bar{3}\)}T and M-(1\(\bar{2}\) 10)//ω(0\(\bar{1}\) 10) and {\(\bar{1}\bar{1}3\)}M//{1\(\bar{2}\) 1\(\bar{3}\)}ω. However, the presence of unstable ω phase, located at the twinning boundary, causes detwinning and forms lath martensite during tempering caused by localized heat during abrasion. Nano-cementite is formed at lath boundaries. Some cracking was observed, but the crack orientation is radial, indicating a response to tangential stresses associated with abrasion as opposed to dynamic stress waves from high-angle impact. Tangential tensile stresses due to surface traction during the abrasion process lead to radial cracks in brittle eutectic carbides, which join up and cause material removal.

Graphical Abstract

中文翻译：

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粉碎过程中高铬白口铸铁的磨损机理及其组织演变

利用透射电子显微镜（TEM）和XRD研究了用于粉碎的白口铸铁磨球的详细变形机理及其微观结构变化。变形是滚珠消耗的主要模式，而滚珠破裂是相对不常见的故障模式。变形是操作过程中引起的磨料磨损的表现，并且磨料磨损伴随着微观结构的变化。微切割是最重要的机制。观察到未使用的研磨球基体的原始微观结构具有ω相孪晶马氏体，取向关系为M-（1 \（\ bar {2} \） 1）// T-（\（\ bar {1 } 2 \ bar {1} \））和{ \（\ bar {1} \ bar {1} 3 \） } M // {11 \（\ bar {3} \）} T和M-（1 \（\ bar {2} \） 10）//ω（0 \（\ bar {1} \） 10）和{ \（\ bar {1} \ bar {1} 3 \ ） } M // {1 \（\ bar {2} \） 1 \（\ bar {3} \） }ω。但是，位于孪晶边界的不稳定ω相的存在会导致脱层并在回火期间由于磨损过程中的局部热量而形成板条马氏体。在板条边界处形成纳米陶土。观察到一些裂纹，但是裂纹的方向是径向的，表明对与磨损相关的切向应力的响应，与来自大角度冲击的动态应力波相反。在研磨过程中，由于表面牵引而产生的切向拉伸应力会导致脆性的共晶碳化物出现径向裂纹，这些裂纹会合在一起并导致材料去除。

图形概要