Influence of Quenching Temperature on Microstructure and Properties of 40Cr Steel by Zero Time Holding Quenching

2011 ◽  
Vol 215 ◽  
pp. 25-28 ◽  
Author(s):  
An Ming Li ◽  
Meng Juan Hu

The effect of quenching temperature on the microstructure and mechanical properties of 40Cr steel by zero time holding quenching were studied. The results showed that the strength and hardness of 40Cr steel increased with the increase of quenching temperature in the range of 860~940°C, the strength and hardness reach the maximum at 920°C and then decrease. The metallographic analysis shows austenite grains of the samples by “Zero Time Holding” Quenching have been refined compared with the traditional heat treatment technology. Fine lath martensite was obtained by the “zero time holding” quenching due to the smaller austenitic crystal grain and the uneven distribution of the carbon concentration in austenitic crystal grain.

2010 ◽  
Vol 163-167 ◽  
pp. 283-287
Author(s):  
An Ming Li ◽  
Meng Juan Hu

The effect of “zero time holding” quenching temperature on the 45 steel’s microstructure and mechanical properties were studied by the orthogonal regressive principle. The 45 steel’s microstructure characteristics with “zero time holding” quenched were analyzed. The results showed that the 45 steel’s strength and hardness increased with the increase of quenching temperature in the range of 780~ 900°C. The grain size in zero time holding was smaller than that with holding time (60 min). The martensite lath was very fine after “zero time holding” quenched. The mechanical properties of the 45 steel Processed by the zero time holding heat treatment is higher than those processed by the conventional heat treatment. The experimental results showed that the properties of the drive shaft with 45 steel were satisfying after they are processed with the “zero time holding”heat treatment technology.


2020 ◽  
Vol 993 ◽  
pp. 492-496
Author(s):  
Peng Xiao Zhu ◽  
Yi Li ◽  
Bo Chen ◽  
Kun Feng

The effects of different zero-holding quenching temperatures on the tempering microstructure, mechanical properties and wear resistance of 40Cr were studied. The results showed that the microstructure of 40Cr was tempered sorbite and a small amount of unmelted ferrite after quenching at 850 °C and tempering at 550 °C for 2 h. Tempered sorbite was obtained after quenching at 880 °C~910 °C and tempering at 550 °C for 2 h. With the increasing of quenching temperature at zero holding temperature, the tensile strength and yield strength of 40Cr increased, while the elongation and impact toughness decreased. With the decreasing of impact test temperature, the ballistic work of 40Cr decreased gradually, and decreased fastest between 0 °C~-20 °C. 40Cr had the best impact performance after quenching at 850 °C and tempering at 550 °C for 2 h. 40Cr had the smallest wear loss after quenching at 880 °C and tempering at 550 °C for 2 h. Its wear marks were smooth, and had the shallowest furrows and ridges.


2008 ◽  
Vol 33-37 ◽  
pp. 459-462
Author(s):  
Zhi Qiang Jiang ◽  
Xi Lan Feng ◽  
Jin Fa Shi

Influence of quenching temperature and cooling speed on the structures and properties of cast Fe-B-C alloy containing more than 1.0%B and lower than 0.2%C was researched. The results showed that the structures of Fe-B-C cast alloy changed from a great of pearlite + a small of martensite 􀄗 a great of martensite + a small of pearlite 􀄗 martensite and the hardness increased with the increase of quenching cooling speed. In the condition of water cooling, higher or lower quenching temperatures were not advantageous to obtaining single martensite. Quenching at 950~1000oC, cast Fe-B-C alloy could obtain the compound structures of fine lath martensite. The hardness and impact toughness of cast Fe-B-C alloy excelled 55HRC and 15J/cm2 respectively.


2017 ◽  
Vol 265 ◽  
pp. 712-716 ◽  
Author(s):  
Mikhail V. Maisuradze ◽  
Maksim Ryzhkov ◽  
Aleksandra A. Kuklina

The CCT diagram of the high strength D6AC steel was plotted using the dilatometer data, microstructure investigation, and hardness measurements. The microstructure of the steel under consideration was estimated after various cooling conditions and quenching and tempering. The heat treatment technology of D6AC steel drill bits was developed to obtain the required mechanical properties.


2012 ◽  
Vol 557-559 ◽  
pp. 34-37
Author(s):  
Jing Qiang Zhang ◽  
Jie Min Du ◽  
Ji Wei Guo ◽  
Shou Fan Rong ◽  
Guang Zhou Wang

The influences of Mn and heat-treatment technology on microstructure and mechanical properties of medium-carbon-low-alloy wear-resistant cast steel were investigated. The results show that the hardness first increases and then drops down with the increase of Mn content, and the best hardness is 54HRC with Mn content 1.5%. The impact toughness first increases and then drops down with the increase of Mn content. The hardness and impact toughness first increase and then drop down with the increases of quenching temperature. The optimal impact toughness can be obtaind by quenching at 920°C and tempering at 200°C. Part of lower bainite and residual austenite and mass of tempered martensite are obtaind after tempering.


2008 ◽  
Vol 575-578 ◽  
pp. 1414-1419 ◽  
Author(s):  
Wen Min Zhao ◽  
Zhen Xu Liu ◽  
Zi Lai Ju ◽  
Bo Liao ◽  
Xue Guang Chen

The type, shape and distribution of carbide take directly effect on the mechanical properties of high chromium castings. Vanadium is able to stabilize the structure of carbide in high chromium cast iron, meanwhile the hardness of carbide containing vanadium can reaches about 2800HV. In some cases, vanadium can also refine the microstructure. Rare-earth is able to change the shape of carbide in cast iron, refine the grain size of ferrite and improve the mechanical properties of castings. In this experiment, intention of adding vanadium and rare-earth is modification of mechanical properties with the proper heat treatment technology. With the help of SEM, the characteristics of carbide, such as shape, distribution and quantity can be observed and mechanical properties have been improved for better wear-resistance.


2012 ◽  
Vol 472-475 ◽  
pp. 978-981
Author(s):  
An Ming Li ◽  
Meng Juan Hu

The pretreatment process is quenching and normalizing, respectively. Influence of different original structures on tensile strength and hardness is investigated. The experimental results show that the as quenched 35CrMo steel by zero time holding quenching obtains fine lath martensite structure and has higher tensile strength and hardness. The mechanical properties of the as quenched 35CrMo steel is better than that of the as normalized 35CrMo steel. The effect of original structure on the mechanical properties of 35CrMo steel is prominent when the zero time holding quenching temperature is lower, but it decreases with the quenching temperature increasing. The austenite inverse transformation zero time holding quenched at low temperature can improve the mechanical properties of 35CrMo steel.


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.


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