Grain refinement of high-strength maraging steels through cyclic heat treatment

1978 ◽  
Vol 33 (1) ◽  
pp. 49-56 ◽  
Author(s):  
K. Nakazawa ◽  
Y. Kawabe ◽  
S. Muneki
Keyword(s):  
Heat Treatment ◽  
Grain Refinement ◽  
High Strength ◽  
Cyclic Heat Treatment ◽  
Maraging Steels ◽  
Cyclic Heat

scholarly journals Wear-Resistance Improvement of 65Mn Low-Alloy Steel through Adjusting Grain Refinement by Cyclic Heat Treatment

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7636
Author(s):  
Ying Tong ◽  
Yu-Qing Zhang ◽  
Jiang Zhao ◽  
Guo-Zheng Quan ◽  
Wei Xiong
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Wear Resistance ◽  
Grain Refinement ◽  
Alloy Steel ◽  
Low Alloy Steel ◽  
Cyclic Heat Treatment ◽  
Average Grain Size ◽  
Cyclic Heat ◽  
Cyclic Quenching

Refined microstructures achieved by cyclic heat treatment significantly contribute to improving the wear resistance of steels. To acquire the refined microstructures of 65Mn low-alloy steel, first, the specimens were solid solution-treated; then, they were subjected to cyclic heat treatment at cyclic quenching temperatures of 790–870 °C and quenching times of 1–4 with a fixed holding time of 5 min. The mechanical properties of 65Mn low-alloy steel in terms of hardness, tensile strength, elongation and wear resistance were characterized. Afterwards, the effect of cyclic heat treatment on microstructure evolution and the relationships between grain refinement and mechanical properties’ improvement were discussed. The results show that the average grain size firstly decreased and then increased with the increase in the quenching temperature. Hardness increased with grain refinement when the temperature was lower than 830 °C. Once the temperature exceeded 830 °C, hardness increased with the temperature increase owing to the enrichment of carbon content in the martensite. With the increase in cyclic quenching times, hardness continuously increased with grain refinement strengthening. In addition, both tensile strength and elongation could be significantly improved through grain refinement. The relationships among wear loss, hardness and average grain size showed that wear resistance was affected by the synthesis reaction of grain refinement and hardness. Higher hardness and refined grain size contributed to improving the wear resistance of 65Mn low-alloy steel.

scholarly journals Effects of Fine Precipitates on Austenite Grain Refinement of Micro-alloyed Steel during Cyclic Heat Treatment

2019 ◽  
Vol 59 (11) ◽  
pp. 2098-2104 ◽  
Author(s):  
Genki Saito ◽  
Norihito Sakaguchi ◽  
Munekazu Ohno ◽  
Kiyotaka Matsuura ◽  
Masayoshi Takeuchi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Refinement ◽  
Alloyed Steel ◽  
Cyclic Heat Treatment ◽  
Austenite Grain ◽  
Cyclic Heat ◽  
Micro Alloyed Steel

Grain Refinement of Ti-48Al-2Cr-2Nb Alloy by Heat Treatment Method

2012 ◽  
Vol 191 ◽  
pp. 221-234 ◽  
Author(s):  
Agnieszka Szkliniarz
Keyword(s):  
Heat Treatment ◽  
Grain Refinement ◽  
Treatment Method ◽  
Cyclic Heat Treatment ◽  
Treatment Processes ◽  
Multi Stage ◽  
Cyclic Heat ◽  
Treatment Procedures ◽  
Heat Treatment Method ◽  
Initial Heat

In this paper, the possibility of refining grain of Ti-48Al-2Cr-2Nb alloy in the processes of multi-stage heat treatment consisted of initial heat treatment, cyclic heat treatment and under-annealing was evaluated. Microstructural changes that take place during the particular heat treatment procedures were also described. It was demonstrated that due to the application of combined cyclic heat treatment and under-annealing almost 24-fold grain refinement in relation to the state after homogenising could be obtained. Probable mechanisms of grain refinement in the proposed heat treatment processes were also presented and influence of individual procedures of the proposed treatment on selected properties of the investigated alloy was described

scholarly journals Improvement of toughness and hardness in BR1500HS steel by ultrafine martensite

2020 ◽  
Vol 39 (1) ◽  
pp. 281-290
Author(s):  
Li-Yong Wang ◽  
Le Li
Keyword(s):  
Heat Treatment ◽  
Heating Temperature ◽  
Heat Rate ◽  
High Strength ◽  
Optical Microscope ◽  
Holding Time ◽  
Cyclic Heat Treatment ◽  
Cyclic Heat ◽  
Lath Width ◽  
Thermal Dilation

AbstractTo obtain the ultrafine martensite for BR1500HS ultra-high-strength steel, a new preparation process of cyclic heat treatment (CHT) with descending heat temperature and holding time along with cycle steps was developed. First, a series of thermal dilation tests were conducted with the temperature range of 420–730°C and the heat rate of 5 K/s on a Gleeble-3800 thermomechanical physical simulator. According to the experimental data, the temperature ranges and the optimal holding time to completely austenitize BR1500HS were determined. Then, to confirm the optimal parameters of CHT for BR1500HS, several tests with various temperatures and cycle steps were conducted and analyzed by optical microscope and scanning electron microscope. Subsequently, the CHTs with decreasing heating temperature and holding time were studied due to the increasing internal energy of steel along with the CHT process. The lath width was measured as a criterion to evaluate the refinement degree in this article. After several loops of heat treatment, the lath width is reduced to 0.268 µm. Finally, the hardness evolution of the specimens subjected to CHT in this study was analyzed and compared with the lath width test results, which justified the effectiveness of the new developed process.

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