表面变质层硬度的压痕表征方法-《郑州大学学报(工学版)》

文章信息/Info

Author(s):: Xu Guangtao; Sun Bo; Chen Haikuan; Zheng Xuefeng;; School of Mechanical and Power Engineering, Zhengzhou University;

Keywords:: Indentation hardness; surface deterioration layer; heat treatment; 18CRNIMO7-6 alloy steel

摘要:: 关键构件经过热处理等表层改性处理后产生的表面变质层，其硬度沿深度梯度变化，如何测量表面变质层硬度是一个亟需解决的问题。本文提出了一种表面变质层硬度的表征方法，根据硬度与深度的关系，使用逐步连续压痕加载将变化的表面变质层硬度进行表征。只要压入深度超过表面变质层深度就能将整个表面变质层的硬度信息提取出来。通过ANSYS有限元仿真建立表面变质层-基体梯度模型，施加连续压痕验证该方法的正确性。对18CrNiMo7-6合金钢进行渗碳热处理，使其表面产生表面变质层，并用该方法表征热处理后的18CrNiMo7-6合金钢的表面变质层硬度。将测量结果与沿表面变质层侧面表征的显微硬度结果进行比较，结果表明该方法能准确的表征表面变质层的真实硬度场。

Abstract:: The hardness of the surface modified la＜x＞yer of key components after surface modification such as heat treatment changes gradiently along the depth. Therefore, it is necessary to study how to measure the hardness of the surface modified la＜x＞yer. According to the relationship between hardness and depth, the hardness of the modified la＜x＞yer was characterized by step-by-step continuous indentation. The hardness information of the whole me＜x＞tamorphic la＜x＞yer can be extracted as long as the penetration depth exceeds the depth of the me＜x＞tamorphic la＜x＞yer. In this paper, a method of modifying the hardness of surface modified la＜x＞yer is proposed. The gradient model of modified la＜x＞yer matrix is established by ANSYS finite element simulation, and the correctness of the method is verified by applying continuous indentation. The surface modification la＜x＞yer was produced on the surface of 18crnimo7-6 alloy steel by carburizing heat treatment. The hardness of modified la＜x＞yer of 18crnimo7-6 alloy steel after heat treatment was characterized by this method. The results show that this method can accurately characterize the real hardness of the me＜x＞tamorphic la＜x＞yer depth