The Influence of Heat Treatment on Microstructure and Mechanical Properties of Cr15 Super Martensitic Stainless Steel

2011 ◽  
Vol 393-395 ◽  
pp. 440-443
Author(s):  
Xin Liu ◽  
Kun Yu Zhao ◽  
Yong Heng Zhou ◽  
Dong Ye ◽  
Wen Jiang ◽  
...  

The microstructure and mechanical properties of 15Cr super martensitic stainless steel after different heat treatments were studied. The results show that the structures of the steel after quenching are lath martensite. With the raising of the quenching temperature, the original austenite grain size increases and the martensite platelet gradually coarsens. The microstructures of the tempered steel are tempered martensite and reversed austenite dispersed in the martensitic matrix.

2012 ◽  
Vol 581-582 ◽  
pp. 954-957
Author(s):  
Wen Jiang ◽  
Kun Yu Zhao ◽  
Dong Ye ◽  
Jun Li ◽  
Zhi Dong Li ◽  
...  

The microstructure and mechanical properties of Cr15 super martensitic stainless steel after different heat treatment were studied by SEM and XRD. The results show that the microstructure of steel A and B are lath martensite and retained austenite after quenching. The original austenite grain size increases with the increasing quenching temperature. The microstructure is composed by tempered martensite and reversed austenite after tempering. The amount of reversed austenite in both steels increases first and then decreases with the increasing tempering temperature. Both of the tested steels have the best mechanical properties at 650°C tempering temperature.


Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 694
Author(s):  
Junaidi Syarif ◽  
Mohammad H. Yousuf ◽  
Zainuddin Sajuri ◽  
Amir Hossein Baghdadi ◽  
Mahdi Merabtene ◽  
...  

The 440C martensitic stainless steel is considered to be among the hardest steels, owing to its high carbon content. Careful heat treatment of this material introduces multiple carbide particles, which can alter microstructure and mechanical properties. This study focused on the effect of austenitisation temperature on the microstructure and tensile properties of 440C steel. Austenitisation was performed on the austenite + carbide region, because 440C steel lacks a single-phase region. The steel was austenitised at two different temperatures; namely, 1160 °C and 950 °C, and subjected to oil quenching. The as-quenched samples showed a typical lath martensite structure with retained austenite phase. The treatments at 1160 °C and 950 °C promoted the formation of M7C3 and M23C6 carbides, respectively. The austenite grains in the sample treated at 1160 °C showed a higher growth rate than those in the sample treated at 950 °C. The sample treated at 1160 °C showed low-fraction and a large-size carbide phase. The Zener pinning force decreased, thereby increasing the austenite grain growth in the sample treated at 1160 °C. The hardness and 0.2% proof stress of the sample treated at 950 °C were higher than those of the sample treated at 1160 °C, owing to the higher martensite content in the former. The strength–ductility balance of the sample treated at 950 °C was higher than that of the sample treated at 1160 °C. The decreased austenitisation temperature resulted in improved mechanical properties of the steel. Therefore, the austenitisation temperature alters the microstructure and mechanical properties of 440C steel.


2011 ◽  
Vol 399-401 ◽  
pp. 211-215
Author(s):  
Yong Heng Zhou ◽  
Kun Yu Zhao ◽  
Xin Liu ◽  
Dong Ye ◽  
Wen Jiang ◽  
...  

There are lath martensite and a little austenite in the microstructure of samples quenched. The original austenite grain sizes ranges from 7.9μm to 74.1μm, which grows up gradually with the increasing of temperature quenching. So do the martensite acicular bundle. During the process of tempering at different temperatures after quenching at 1050°C, austenite grain size becomes bigger with the temperature increasing, and martensite acicular bundle becomes thinner. The content of austenite ascends to the peak at 650°C then it decreases. The mechanical properties (σb =958.87 MPa, δ=20.44%, HRC=30.9) of the samples are the best, when quenching temperature is 1050°C and tempering temperature is 600°C.


2021 ◽  
Vol 118 (6) ◽  
pp. 601
Author(s):  
Chunhui Jin ◽  
Honglin Zhou ◽  
Yuan Lai ◽  
Bei Li ◽  
Kewei Zhang ◽  
...  

The influence of aging temperature on microstructure and mechanical properties of Cr15Ni5 precipitation hardening stainless steel (15-5 PH stainless steel) were investigated at aging temperature range of 440–610 °C. The tensile properties at ambient temperature of the 15-5 PH stainless steel processed by different aging temperatures were tested, and the microstructural features were further analyzed utilizing optical microscope (OM), transmission electron microscope (TEM), electron backscatter diffraction (EBSD) as well as X-ray diffraction (XRD), respectively. Results indicated the strength of the 15-5 PH stainless steel was firstly decreased with increment of aging temperature from 440 to 540 °C, and then increased with the increment of aging temperature from 540 to 610 °C. The strength and ductility were well matched at aging temperature 470 °C, and the yield strength, tensile strength as well as elongation were determined to be 1170 MPa, 1240 MPa and 24%, respectively. The microstructures concerning to different aging temperatures were overall confirmed to be lath martensite. The strengthening mechanisms induced by dislocation density and the second phase precipitation of Cu-enriched metallic compound under different aging temperatures were determined to be the predominant strengthening mechanisms controlling the variation trend of mechanical properties corresponding to different aging temperatures with respect to 15-5 PH stainless steel.


Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1414
Author(s):  
Fei Huang ◽  
Jian Chen ◽  
Zhangqi Ge ◽  
Junliang Li ◽  
Yongqiang Wang

The effect of austenitizing temperature and aging treatment on the microstructure and mechanical properties of two new cold-rolled automotive steel plates (20Mn2Cr and 20Mn2CrNb) was investigated by using isothermal heat treatment, optical microscope, scanning electron microscope, microhardness tester, and tensile testing machine. The results show that as the austenitizing temperature increased, the original austenite grain sizes of both steels increased. The original austenite grain size of 20Mn2CrNb was smaller than that of 20Mn2Cr. The microhardness of 20Mn2CrNb gradually decreased with increasing aging temperature, while the hardness of 20Mn2Cr varied irregularly. The mechanical properties of 20Mn2Cr were better than those of 20Mn2CrNb under the same heat-treatment process. The effect of heat treatment on microstructure and mechanical properties was related to the martensite content, dislocation density, and precipitation of second-phase particles.


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