Effect Of Element B On Microstructure And Properties Of Fe-based Laser Shaped Samples

With the development of manufacturing industry in recent years,changing composition and content of trace elements of steel products for good organization and performance will be concerned as a new subject.In this paper,different contents of trace element boron on the microstructure and mechanical properties of Fe based alloys laser formed sample are researched,the effect of Boron on the microstructure and echanical properties of Fe based alloy laser formed specimen was investigated,accumulate data for its industrial applications.In this paper,X ray diffraction(XRD),optical microscopy(OM)and scanning electron microscopy(SEM)are used,to study The effects of element B on the phase,macroscopic and microstructure of laser rapid prototyping.Based on the observation and analysis of the macroscopic of the formed samples: surface quality of the sample was well,with good metallurgical bond to the substrate.In terms of organization,with the increase in element B,the grain size of the martensite forming sample is obviously increased.In the austenitic laser forming sample,the grain size of the samples increases first and then decreases with the increase of thecontent of B,when the B content is 1.0%,the grain size is the smallest.A type of TH320 Luo's hardness tester was used to measure the hardness of the laser rapid forming sample,a PWS-E100 universal testing machine was used to test the mechanical properties of the sample forming.According to the stress of the parts in the work,the tensile properties?hardness and fatigue properties of the specimens were studied.In the austenitic forming sample,hardness and tensile strength of the material decrease as the B contents increasing,and then increasd with increasing B contents.the hardness of 36.2HRC,the tensile strength of 1011 MPa and the fatigue strength of 556 MPa when the B content reached 1.0wt%.In the martensitic forming sample,hardness and tensile strength of the material decrease as the B contents increasing,the hardness of 57.7HRC,the tensile strength of 1591 MPa and the fatigue strength of 636.4MPa when the B content reached 0.1wt%.