Development of the peening processes micropeening and ultrasonic wet peening to work hardening

开发微喷丸和超声波湿喷丸加工硬化喷丸工艺

基本信息

批准号：
240450756
负责人：
Professor Dr.-Ing. Volker Schulze
金额：
--
依托单位：
Institut für Angewandte Materialien - Werkstoffkunde (IAM-WK)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/240450756?language=en
关键词：
Development peening processes micropeening ultrasonic

项目摘要

The processes micro-peening and ultrasonic wet peening offer the possibility of mechanical surface treatment to significantly increase fatigue strength of steels, with several advantages over established methods such as shot peening. This includes not only a high surface quality with little effect of blasting media impacts on the roughness but also a very low peening intensity, which allows for the processing of thin-walled components. Another notable effect is the occurrence of nanocrystalline regions on the surface, which affect the mechanical properties of the boundary layer. In the first phase of the grant Armco iron was used as the model material to separate the factors influencing the fatigue strength and are based on developed and validated a material model of grain refinement and consolidation of a modified concept of local endurance. In the second phase of the project this understanding of the mechanisms will now be transferred to the quenched and tempered steel 42CrMo4 V450. This bears the difficulty that a parameter separation by heat treatment as in the Armco iron, is not possible. Furthermore, the individual states of the boundary layer cannot be clearly separated in this heat treatment condition. In addition, the heavily modified deformation behavior, which also affects the surface layer state, must be considered in the modelling approach. The concept to be developed on the basis of previous FEM simulations will also be validated with an experimental characterization of the microstructure and the fatigue behavior. This is to be finally applied to a sequential mechanical surface treatment of conventional shot peening followed by micro-peening or ultrasonic wet peening. This should achieve an optimized combination of high penetration with optimized near-surface properties so that a significant increase in lifetime results for thick-walled components.

微喷丸和超声波湿喷丸工艺提供了机械表面处理的可能性，可显着提高钢材的疲劳强度，与喷丸等现有方法相比具有多种优势。这不仅包括高表面质量，喷砂介质对粗糙度的影响很小，而且还包括非常低的喷丸强度，从而可以加工薄壁部件。另一个显着的影响是表面出现纳米晶体区域，这会影响边界层的机械性能。在拨款的第一阶段，Armco 铁被用作模型材料，以分离影响疲劳强度的因素，并基于开发和验证的晶粒细化材料模型以及局部耐久性修改概念的巩固。在该项目的第二阶段，这种对机制的理解现在将转移到调质钢 42CrMo4 V450 上。这带来了一个困难，即不可能像 Armco 铁一样通过热处理进行参数分离。此外，在这种热处理条件下，边界层的各个状态不能清楚地区分。此外，在建模方法中必须考虑严重修改的变形行为，这也会影响表面层状态。基于先前有限元模拟开发的概念还将通过微观结构和疲劳行为的实验表征进行验证。这最终将应用于传统喷丸的连续机械表面处理，然后是微喷丸或超声波湿喷丸。这应该实现高穿透力与优化近表面特性的优化组合，从而显着延长厚壁部件的使用寿命。