SS304 Stainless Steel Clad Steel Plate For Heat Exchanger

The specific research object is the composite plate with the most widely used stainless steel cladding in modern industry. The SS304 Stainless Steel Clad Steel Plate for Heat exchanger is SUS304 stainless steel (06Cr19Ni10), and the base plate is Q345R carbon steel. The chemical composition and physical properties of the two materials are shown in Table 21 and Table 22 respectively.

According to the calculation, the best theoretical collision point moving speed is 2334m/s. It can be determined that the detonation velocity of the explosive used should be about 234m/s. Industrial explosives with lower detonation velocity are required. Low detonation velocity explosive can effectively reduce or even eliminate the harmful effect of the residual energy of explosive explosion on the SS304 Stainless Steel Clad Steel Plate for Heat exchanger, and improve the welding quality of the composite plate by 3. The basic principle of the design of low detonation velocity industrial explosives is to add compatible diluents to the explosive components. The explosive used in this experiment is an expanded ammonium nitrate explosive with diluent (expanded AN 82.8%, wood flour 36%, fuel oil 3.6%, perlite 10% 40), with a density of about 065gcm3 and detonation velocity of about 240ms.

When the charge thickness is close to the maximum value, on the one hand, the demand for explosives is very high, and the spacing range is difficult to choose, which will cost a lot in actual engineering application, and the risk is very high; On the other hand, according to the previous analysis, if the dosage is too large, it is easy to produce the so-called "over dissolution" phenomenon on the bonding interface, that is, the bonding interface accumulates too much energy due to too fast collision speed so that the interface is in a long-term melting state. If the time is greater than the time of reflecting back the sparse wave from the free interface, Then the bonding interface will be separated due to the effect of rarefaction wave, which will seriously affect the quality of glow bonding, so it is not advisable to take a value close to the maximum value.

According to the theoretical formula, a computer program related to window theory and process conditions is compiled, which simplifies the tedious calculation process in theoretical research and engineering research, improves work efficiency, and provides convenience for research. When the distance is fixed, the wavelength and amplitude of the interface waveform will increase with the increase of the charge amount. The bonding strength of the interface is positively correlated with wavelength and amplitude at first and negatively correlated with wavelength and amplitude after reaching a certain extent. The influence of charge amount on bonding strength increases with the increase of cladding thickness. The selection method of the optimal charge amount is related to the thickness of the cladding plate: when the thickness of the cladding plate (sUS304) is thin (3mm in the text), the charge amount should be higher than the theoretical optimal value; when the thickness of the cladding plate (SUS304) is thick (6mm in the text), the charge amount should be lower than the theoretical lower limit value. In actual production, for the explosive cladding of SUS304 and Q345R, when the cladding plate is thin (in the text, if the bonding quality of the cladding plate is given priority, the charge height should be 30mm; if the production cost is given priority, the charge height can be 15mm, so the bonding quality of the cladding plate obtained also meets the standard requirements; when the cladding plate is thick (in the text, 6mm), The effect is better when the propellant height is 25 mm. The velocity of the composite plate has a process from increasing to decreasing during the movement, and the velocity will still fluctuate even after the collision. When the charge amount is fixed, with the increase of the selected spacing, the wavelength and amplitude of the interface waveform obtained by different processes first increase and then decrease. When the thickness of the cladding plate (SUS304) is 3mm, the spacing of 8mm is a good value. Different charges have little influence on the value of the optimal spacing The pressure at the interface is getting bigger and bigger along the direction of detonation wave propagation, and the pressure at the interface at the boundary is relatively small due to the "boundary effect". In actual production, attention should be paid to Within a certain range, when the wavelength of the interface wave is the same, the smaller the amplitude is, the higher the bonding strength of the interface is. The model and parameters for numerical simulation in this paper are selected reasonably, The description of the motion state, velocity, and interface pressure of the calculated results is in good agreement with reality.