Influence of cooling rate on the precipitation behavior in Ti–Nb–Mo microalloyed steels during continuous cooling and relationship to strength

2015 ◽  
Vol 102 ◽  
pp. 146-155 ◽  
Author(s):  
F.Z. Bu ◽  
X.M. Wang ◽  
L. Chen ◽  
S.W. Yang ◽  
C.J. Shang ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Microalloyed Steels ◽  
Precipitation Behavior ◽  
Continuous Cooling

scholarly journals Copper Precipitation Behavior during Continuous Cooling and Subsequent Aging of Powder-Forged Fe-2.5Cu-C Alloy

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1350
Author(s):  
Sui Wang ◽  
Yake Wu ◽  
Tengyu Zhang ◽  
Feng Jiang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
High Performance ◽  
Theoretical Calculations ◽  
Combined Effects ◽  
Precipitation Behavior ◽  
Subsequent Aging ◽  
Continuous Cooling ◽  
Copper Precipitation ◽  
Secondary Precipitates

Microstructure and property evolution of a powder-forged Fe-2.5Cu-C alloy during continuous cooling and subsequent aging were investigated to improve its mechanical properties. During continuous cooling, copper precipitates formed were consistent with the interphase mechanism when the cooling rate was less than 7 °C/s; however, the hardness of the specimen was always higher at faster cooling rates because finer grains and harder phases formed. During subsequent aging, copper precipitates formed and/or coarsened continuously while the hardness of the alloys was greatly influenced by the combined effects of the primary and secondary precipitates, as revealed by the theoretical calculations. In addition, the forming and evolving mechanisms of the copper precipitates at different stages were also discussed based on the experimental results. This study will provide guidance to the industry for achieving high performance in the powder-forged products by treatment manipulation.

Precipitation Behavior of Steels with Various Copper during Continuous Cooling

2010 ◽  
Vol 638-642 ◽  
pp. 3573-3578 ◽  
Author(s):  
Xue Min Wang ◽  
Chuang Li ◽  
Cheng Jia Shang ◽  
Chang An Zheng ◽  
Xin Lai He
Keyword(s):  
Cooling Rate ◽  
Rate Increase ◽  
Optical Microscope ◽  
Precipitation Process ◽  
Second Phase ◽  
Precipitation Behavior ◽  
Phase Form ◽  
Continuous Cooling ◽  
Bearing Steels ◽  
Hardness Tests

The precipitation behavior of several Cu-bearing steels with various copper contents during continuous cooling has been studied. The optical microscope and HRTEM were employed to study the influence of cooling rate on the precipitation process. Also, the hardness of samples with different processes is tested. The results show that when the steels was cooled at a cooling rate between 0.1-1°C/s with the cooling rate increasing the second phase precipitates become finer but the precipitates become denser. When the cooling rate is 1°C /s the density of the second phase precipitates are the largest. When the cooling rate is quicker than 1°C /s as the cooling rate increase the precipitates become finer and fewer. The hardness tests also show that the sample will get the highest hardness. When the samples are cooled at a rate larger than 5°C /s， there is few precipitates in samples. The copper-rich second phase form by Inter-phase precipitation, and the copper-rich phase i.e. G.P zone is the main cause to strengthen the alloy. As the copper content varies from 1.5wt% to 2.5wt% the highest hardness could be obtain when the samples is cooled at a rate of 1°C /s and the density of the precipitates is the largest

Hardenability of Medium Carbon Cr-Mn-Mo Alloyed Steels

2019 ◽  
Vol 946 ◽  
pp. 341-345
Author(s):  
Mikhail V. Maisuradze ◽  
Maksim A. Ryzhkov
Keyword(s):  
Cooling Rate ◽  
Structural Steels ◽  
Alloying Elements ◽  
Metallographic Analysis ◽  
Medium Carbon ◽  
Austenite Transformation ◽  
Continuous Cooling ◽  
Different Content ◽  
Cct Diagrams

Three medium carbon Cr-Mn-Mo structural steels with different content of alloying elements were studied. The austenite transformation during continuous cooling was investigated using dilatometer and metallographic analysis. The CCT diagrams were plotted showing the effect of the increased alloying elements content and B and Nb micro-alloying on the hardenability of the studied steels. The hardness dependences on the cooling rate were obtained.

Continuous Cooling Transformation of Overcooling Austenite and Structure Evolution of Si Steel

2013 ◽  
Vol 652-654 ◽  
pp. 947-951
Author(s):  
Hui Li ◽  
Yun Li Feng ◽  
Da Qiang Cang ◽  
Meng Song
Keyword(s):  
Phase Transformation ◽  
Cooling Rate ◽  
Optical Microscope ◽  
Structure Evolution ◽  
Upward Trend ◽  
Continuous Cooling Transformation ◽  
Continuous Cooling ◽  
Hardness Tester ◽  
Gleeble 3500 ◽  
Evolution Of Microstructure

The static continuous cooling transformation (CCT)curves of 3.15 Si-0.036 C-0.21 Mn-0.008 S-0.008 N-0.022 Al are measured on Gleeble-3500 thermal mechanical simulator, the evolution of microstructure and the tendency of hardness are investigated by optical microscope (OM) and hardness tester. The results show that there is no evident change in microstructure which mainly are ferrite and little pearlite under different cooling rates, but the transition temperature of ferrite is gradually reduced with the increase of cooling rate. When the cooling rate is increased from 0.5°C/s to 20°C/s, the ending temperatures of phase transformation are decreased by 118°C, when cooling rate reaches to 10, Widmanstatten ferrite appears. The hardness of the steel turns out gradual upward trend with the increase of cooling rate.

Effect of Cooling Rate on the Precipitation Behavior of Carbonitride in Microalloyed Steel Slab

2010 ◽  
Vol 42 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Fanjun Ma ◽  
Guanghua Wen ◽  
Ping Tang ◽  
Guodong Xu ◽  
Feng Mei ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Microalloyed Steel ◽  
Precipitation Behavior ◽  
Steel Slab

Continuous Cooling Transformation Behavior of High Carbon Pearlitic Steel

2022 ◽  
Vol 905 ◽  
pp. 83-87
Author(s):  
Lu Lu Feng ◽  
Wei Wen Qiao ◽  
Jian Sun ◽  
De Fa Li ◽  
Ping Ping Li ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Vickers Hardness ◽  
Hardness Test ◽  
Pearlitic Steel ◽  
Transformation Behavior ◽  
High Carbon ◽  
Continuous Cooling Transformation ◽  
Continuous Cooling ◽  
Test Steel ◽  
Lamellar Pearlite

The continuous cooling transformation behavior of high-carbon pearlitic steel was studied by employing optical microscopy, scanning electron microscopy, and the Vickers hardness test. The results show that the microstructure of the test steel is composed of proeutectoid cementite and lamellar pearlite in the cooling rate range of 0.05–2 °C/s and lamellar pearlite in the range of 2–5 °C/s. Further, martensite appears at 10 °C/s. With the increase in the cooling rate, the Vickers hardness of the test steel first decreases and then increases. In the industrial production of high-carbon pearlite steel, the formation of proeutectoid cementite at a low cooling rate needs to be avoided, and at the same time, the formation of martensite and other brittle-phase at a high cooling rate needs to be avoided.

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