The Basic Applied Research On Chrome-RE-boronized Technology

In order to expand the applied range of B-Cr-RE technology and find some new methods to investigate strengthened surface after some surface technology, this paper has studied oxidation weight increase, thermal expansion coefficient of the specimens with thermal analysis technology. The method capturing data output by thermal analyzer, processing the data with some mathematical analysis and then using polynomial or linear fits of the curves to try to get the general idea and keep away from less important interfering factors.Because this method has used so many curve fitting functions to find out the rule of the fact, It was then named curve fitting thermal analysis method.The oxidation weight increase kinetics of B-Cr-RE co-penetrated layer was also studied, and the equation put forward has some universality in its applicability for different oxidizing conditions such as in the air and in oxygen saturation environment, different specimens including matrix material like plain carbon steel and material strengthened by surface technology like B-Cr-RE technology.A method to get the empirical formula of the material strengthened by surface technology has been discussed by TMA ,it can be used to estimate or correct some metallic thermal expansion co-efficient which are hard to measure or hard to measure exactly. In contrast to any other methods ,it combines the thermal expansion coefficients of the matrix material and that after surface treatment, so if we know the coefficient of matrix material ,we can use the method to obtain the coefficient of the material after surface strengthened technology, and there are too many ways to get the matrix thermal expansion coefficient.Mechanical properties of B-Cr-RE co-penetrated layer was also discussed through compression testing, pulling test and bending test, because the strengthened layer was so thin that the way to learn its mechanical properties was difficult. By applying the method brought forward in this paper, we could treat the matrix and strengthened layer as a whole when testing but recorded the corresponding data when the crack on the surface firstly turns up , afterwards, we could handling these data and build the model to research the mechanical properties and get the parameters Such as E , 6 b and etc.