上游充通大率 SHANGHAI JIAO TONG UNIVERSITY Principles of Materials Processing Part Ill 全属材料热处理原理 Heat Treatment Principles of Metals Lecturer:Ke Chen 2017-06-02
Principles of Materials Processing Part III - 金属材料热处理原理 Heat Treatment Principles of Metals Lecturer: Ke Chen 2017-06-02
Outline for Chapter 11 上游充道大粤 SHANGHAI JIAO TONG UNIVERSITY Chapter 11:Precipitation transformations 11.1 Precipitation and Aging 11.1.1 Introduction 11.1.2 Continuous Precipitation 11.1.3 Discontinuous Precipitation 11.2 Tempering of Ferrous Martensite AIJIAO TONG UNI K.Chen 2
K. Chen Chapter 11: Precipitation transformations 11.1 Precipitation and Aging 11.1.1 Introduction 11.1.2 Continuous Precipitation 11.1.3 Discontinuous Precipitation 11.2 Tempering of Ferrous Martensite Outline for Chapter 11 2
Introduction 上游充通大粤 SHANGHAI JIAO TONG UNIVERSITY ©Precipitation: (Co)→o(C1)+B © Slow cooling vs.Quenching M Solution treatment T Quenching a+B T Artificial aging Room Temp. L Natural aging A CI Co B%→ Time→ K.Chen 3
K. Chen Precipitation: Slow cooling vs. Quenching Introduction 3 α(C0 ) →α(C1) + β Solution treatment Quenching Artificial aging Natural aging Time Room Temp. Temp
Introduction 上游充道大粤 SHANGHAI JIAO TONG UNIVERSITY Ageing(时效)： ■ When a precipitation hardening alloy is quenched after solution treatment,its alloying elements will be trapped in solution,resulting in a soft metal. ■ Aging a“solutionized”(固溶处理)metal will allow the alloying elements to diffuse through the microstructure and form intermetallic particles. Natural aging(自然时效)：aging at room temperature Artificial aging(人工时效)：aging at elevated temperature K.Chen 4
K. Chen Ageing (时效): When a precipitation hardening alloy is quenched after solution treatment, its alloying elements will be trapped in solution, resulting in a soft metal. Aging a “solutionized” (固溶处理) metal will allow the alloying elements to diffuse through the microstructure and form intermetallic particles. Natural aging (自然时效): aging at room temperature Artificial aging (人工时效): aging at elevated temperature Introduction 4
Introduction 上游充道大粤 SHANGHAI JIAO TONG UNIVERSITY ©→Precipitation hardening(沉淀强/硬化)or ageing hardening(时效强/硬化) Continuous precipitation vs.Discontinuous precipitation ■ Continuous (precipitation (or general precipitation): it occurs generally throughout the matrix on dislocations or grain boundaries,etc.and the composition of matrix surrounding the precipitates decreases continuously with time Discontinuous(不连续)precipitation(or cellular precipitation,胞状脱溶)：the composition of the matriⅸ changes discontinuously as the cell front passes K.Chen 5
K. Chen Precipitation hardening (沉淀强/硬化) or ageing hardening (时效强/硬化) Continuous precipitation vs. Discontinuous precipitation Continuous (连续) precipitation (or general precipitation): it occurs generally throughout the matrix on dislocations or grain boundaries, etc. and the composition of matrix surrounding the precipitates decreases continuously with time Discontinuous (不连续) precipitation (or cellular precipitation, 胞状脱溶): the composition of the matrix changes discontinuously as the cell front passes Introduction 5