Microstructure control and ultra-high strengthening of stainless steel by the room temperature recrystallization

室温再结晶不锈钢的显微组织控制和超高强化

基本信息

批准号：
10450263
负责人：
AMEYAMA Kei
金额：
$ 5.44万
依托单位：
Ritsumeikan University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

The high strain powder metallurgy (HS-PM) process is a novel powder metallurgy process combining mechanical milling (MM) or mechanical alloying (MA), heat treatment and sintering processes, and enables one to produce an ultra-fine grain structure. It has three remarkable features : [1] a non equilibrium phase, [2] a nano grain microstructure, and [3] good workability. The extremely high strain energy given by the milling process at room temperature produces a large number of defects and this enhances the diffusion of atoms at low temperature and contributes to the formation of a non equilibrium phase such as a supersaturated solid solution or an amorphous phase. A nano grain structure is obtained from the non-equilibrium phases by controlling the heat treatment conditions, which influences the phase transformation, recovery, recrystallization, grain growth, etc (2). Grain refinement is very important to improve the mechanical properties of materials, and fine grained materials easily deform by superplasticity. Therefore, the HS-PM process is the most efficient and useful non-equilibrium powder metallurgy process because it permits simultaneous improvement of mechanical properties and workability by the control of microstructure.In this report, the HS-PM process was applied to an SUS316L stainless steel, and the mechanical properties of the material at room temperature as well as the microstructural changes during the process are discussed. The HIP compact of the HS-PM processed powder showed ultra-fine microstructure with a homogeneously dispersed σphase. The HIP compact also showed outstanding mechanical properties at room temperature as well as at the elevated temperatures.

高应变粉末冶金（HS-PM）工艺是一种结合了机械铣削（MM）或机械合金化（MA）、热处理和烧结工艺的新型粉末冶金工艺，能够产生超细晶粒结构。三个显着特征：[1]非平衡相，[2]纳米晶粒微观结构，[3]良好的加工性，室温铣削过程产生的极高应变能会产生大量缺陷，从而提高了加工性能。扩散通过控制热处理条件，可以从非平衡相中获得纳米晶粒结构，从而影响相变。、回复、再结晶、晶粒长大等(2)晶粒细化对于提高材料的力学性能非常重要，而细晶粒材料很容易因超塑性而变形，因此HS-PM工艺是最有效和有用的。非平衡粉末冶金工艺，因为它可以通过控制微观结构同时提高机械性能和可加工性。在本报告中，HS-PM工艺应用于SUS316L不锈钢，材料在室温下的机械性能为以及在此过程中微观结构的变化，HS-PM 加工粉末显示出超细的微观结构，具有均匀分散的 σ 相，HIP 压坯在室温下也表现出出色的机械性能。温度以及高温下。