| Austenitic stainless steel clad plate has been used in production, but there have been real problems decrease in corrosion resistance, mechanical properties decline in engineering. Explosive welding is a good moldability, processing more convenient molding method, in which the process will produce greater stress, must be subjected to heat treatment. Given the impact of heat treatment on the corrosion resistance of stainless steel, by means of optical microscopy, scanning electron microscopy (SEM), universal testing machine, electrochemical workstation, scanning electrochemical microscopy (SECM) and field emission electron microscopy and EBSD attachment and other equipment, for the current using more 316L / Q345R composite panels, carried out heat treatment were studied microstructure, mechanical properties, corrosion resistance.The results showed that, after heat treatment, composite boards internal stress level decreased significantly after 580?,720?,900? after heat stress levels were decreased by the 1.41 to 0.92,0.90,1.09; tissue deformation after heat treatment has been an explosion inside the state reply recrystallization, Q345R and 316L have both been engaging portion diffusion layer, pearlite Q345R appeared faded inside of when incubated at 720?, while holding the ball at 900?; many sub-grain structure in the presence of explosive state 316L, gradually growing to full heat treatment, so that the total length of the grain boundaries at 580? increased by the average grain size becomes 41 ?m and 32?m, when incubated at 720? and 900? long to 57?m and 67?m.The testing results showed that the mechanical properties, high tensile strength and yield strength of the explosion state, respectively 685Mpa,618 Mpa,580?,720?,900? treated samples due to the elimination of work-hardening, anti yield strength decreases its value respectively 313 Mpa,303 Mpa,307 Mpa, elongation also increased from 20.7% to 40%; low temperature impact properties of composite explosive state board is also low for 40.63J, and after 580?,720? and 900? insulation the impact of the sample values were reached 123.01J,99.63J,155.77J.The four states (state explosion,580? insulation 3h,720? insulation 1.5h,900? insulation 0.5h) were performed at the grain boundary corrosion test results show that after the sample heat-treated 900? corrosion rate is slow, and its the first period and the corrosion rate of the second period were 141.219 g/(m2·h),133.019 g/(m2·h), and it is also the smallest corrosion rate ratio,0.29, small intergranular corrosion tendency, E law also It proves that no cracks after bending; FeCl3 immersion test showed corrosion rate 900? treatment is 33.7 g/ (m2·h), also ideal than the other three states; its corrosion potential is also the largest. SECM analysis showed differences in the corrosion resistance combined area of each location, combined with its near-surface 100?um maximum current within roughly reflects the corrosion resistance of the diffusion regions, which are explosive state 890PA,580? to 740PA,720? to 605PA,900? to 865PA, but the corrosion resistance of the diffusion region does not completely overlay 316L corrosion resistance of a positive correlation.The EBSD analysis of 316L grain boundary confirmed that low ?CSL (CSL<29) will affect the ratio of the grain boundary corrosion resistance, explosion-state,580? heat treatment,720? heat treatment, the proportion of low ?CSL after 900? heat treatment were 47%,37%,57%,67%. The higher the proportion of low ?CSL grain boundaries, the better the corrosion resistance, which is consistent with the corrosion resistance test results. Texture analysis revealed the presence of symmetry in 316L has been good, low energy{001}<100> and {110}<001> cube cubic texture, texture strong internal explosion state and the distribution of randomness, which with its molding characteristics are closely related to the internal heat-treated sample texture waning. |
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