Hot Deformation Behavior and Processing Map of Spray Formed M3��2 High Speed Steel
Lin LU1,Long-gang HOU1,Hua CUI1,Jin-feng HUANG1,Yong-an ZHANG2,Ji-shan ZHANG1
1. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing,Beijing 100083, China 2. State Key Laboratory of Non-ferrous Metals and Process, General Research Institute for Non-ferrous Metals, Beijing 100088, China
Hot Deformation Behavior and Processing Map of Spray Formed M3��2 High Speed Steel
Lin LU1,Long-gang HOU1,Hua CUI1,Jin-feng HUANG1,Yong-an ZHANG2,Ji-shan ZHANG1
1. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing,Beijing 100083, China 2. State Key Laboratory of Non-ferrous Metals and Process, General Research Institute for Non-ferrous Metals, Beijing 100088, China
ժҪ Hot deformation behavior of a new type of M3��2 high speed steel with niobium addition made by spray forming was investigated based on compression tests in the temperature range of 950-1150 �� and strain rate of 0.001-10 s-1. A comprehensive constitutive equation was obtained, which could be used to predict the flow stress at different strains. Processing map was developed on the basis of the flow stress data using the principles of dynamic material model. The results showed that the flow curves were in fair agreement with the dynamic recrystallization model. The flow stresses, which were calculated by the comprehensive constitutive equation, agreed well with the test data at low strain rates (��1 s-1). The material constant (��), stress exponent (n) and the hot deformation activation energy (QHW) of the new steel were 0.00615 MPa-1, 4.81 and 546 kJ��mol-1, respectively. Analysis of the processing map with an observation of microstructures revealed that hot working processes of the steel could be carried out safely in the domain (T=1050-1150 ��, =0.01-0.1 s-1) with about 33% peak efficiency of power dissipation (��). Cracks was expected in two domains at either lower temperatures (��1000 ��) or low strain rates (0.001 s-1) with different cracking mechanisms. Flow localization occurred when the strain rates exceeded 1 s-1 at all testing temperatures.
Abstract��Hot deformation behavior of a new type of M3��2 high speed steel with niobium addition made by spray forming was investigated based on compression tests in the temperature range of 950-1150 �� and strain rate of 0.001-10 s-1. A comprehensive constitutive equation was obtained, which could be used to predict the flow stress at different strains. Processing map was developed on the basis of the flow stress data using the principles of dynamic material model. The results showed that the flow curves were in fair agreement with the dynamic recrystallization model. The flow stresses, which were calculated by the comprehensive constitutive equation, agreed well with the test data at low strain rates (��1 s-1). The material constant (��), stress exponent (n) and the hot deformation activation energy (QHW) of the new steel were 0.00615 MPa-1, 4.81 and 546 kJ��mol-1, respectively. Analysis of the processing map with an observation of microstructures revealed that hot working processes of the steel could be carried out safely in the domain (T=1050-1150 ��, =0.01-0.1 s-1) with about 33% peak efficiency of power dissipation (��). Cracks was expected in two domains at either lower temperatures (��1000 ��) or low strain rates (0.001 s-1) with different cracking mechanisms. Flow localization occurred when the strain rates exceeded 1 s-1 at all testing temperatures.
Lin LU,Long-gang HOU,Hua CUI,Jin-feng HUANG,Yong-an ZHANG,Ji-shan ZHANG. Hot Deformation Behavior and Processing Map of Spray Formed M3��2 High Speed Steel[J]. �й������ڿ���, 2016, 23(5): 501-508.
Lin LU,Long-gang HOU,Hua CUI,Jin-feng HUANG,Yong-an ZHANG,Ji-shan ZHANG. Hot Deformation Behavior and Processing Map of Spray Formed M3��2 High Speed Steel. Chinese Journal of Iron and Steel, 2016, 23(5): 501-508.
2016, Vol. 23 
