By adopting the alloy wire of Ni 80 Cr 20 as the welding core and adding the alloy elements of B, Si, Mo and W into the outer plating covering, a new type of wear resistant overlay welding rod of Ni Cr B Si was develo...By adopting the alloy wire of Ni 80 Cr 20 as the welding core and adding the alloy elements of B, Si, Mo and W into the outer plating covering, a new type of wear resistant overlay welding rod of Ni Cr B Si was developed. This overlay welding rod has several properties such as low melting point and good fluidity. With low content of W and Mo, the wearability and crack resistance of the overlay welding rod can be increased, and the hardness can be increased to about HRC64. This kind of overlay rod has been applied to the overlay of wearable workpieces, such as the valves of high temperature, high pressure and the side plates of floor boarding brick die.展开更多
Copper base alloy was overlaid onto 35CrMnSiA steel plate by tungsten inert gas （TIG） welding method. The heat transfer process was simulated, the microstructures of the copper base overlay were analyzed by scanning...Copper base alloy was overlaid onto 35CrMnSiA steel plate by tungsten inert gas （TIG） welding method. The heat transfer process was simulated, the microstructures of the copper base overlay were analyzed by scanning electron microscopy （SEM） and energy dispersive spectrometer （EDS）, and the friction and abrasion properties of the overlay were measured. The results show that the Fe content increases in the overlay with increasing the welding current. And with the increase of Fe content in the overlay, the friction coefficient increases and the wear mechanism changes from oxidation wear to abrasive wear and plough wear, which is related to the size and quantity of Fe grains in the overlay. While with the increase of Fe content in the overlay, the protection of oxidation layer against the oxidation wear on the melted metal decreases.展开更多
The effects of chemical compositions and microstructures on wearability properties of overlaid corrugating roll were studied, and the factors governing the hardness and the wearability of overlaid layer were explored....The effects of chemical compositions and microstructures on wearability properties of overlaid corrugating roll were studied, and the factors governing the hardness and the wearability of overlaid layer were explored. The results show that the hardness and wearability of the overlaid layer significantly rise with the increase of the mass fraction of various types of eutectic, but the crack-resistance falls. The chief factor governing the hardness of overlaid layer is the matrix microstructure, especially the amount of austenite; and the second is the amount of carbide. The principal factor governing the wearability of overlaid layer is the amount of special carbide, particularly the amount of eutectic; and the second is the hardness of overlaid layer. Meanwhile, high alloying electrodes may cause the gear-surface hardness of corrugating roll to be higher than 63HRc, and may enhance the wearability of the gear-surface of corrugating roll by a factor of 5.63 and 9.08.展开更多
The manuscript presents the results from the electrochemical noise (EN) monitoring of Inconel 82 weld overlay on Type 304L stainless steel (SS) weld in 0.01M FeCl3. The microstructure of the weld overlay obtained from...The manuscript presents the results from the electrochemical noise (EN) monitoring of Inconel 82 weld overlay on Type 304L stainless steel (SS) weld in 0.01M FeCl3. The microstructure of the weld overlay obtained from optical and scanning electron microscopy (SEM) showed an austenite structure, containing equiaxed dendrites and secondary phases at the interdendritic region. Energy dispersive spectroscopy (EDS) attached to SEM revealed the secondary phases to be Nb rich Laves phase. The electrochemical potential noise was monitored using a three identical electrode configuration. The acquired signals were detrended, and wavelet analysis was employed to encode useful information from the noise transients. Visual examination of the potential noise-time record contained distinct high amplitude transients typical of localized corrosion attack. The energy distribution plots (EDP) of the potential noise derived from wavelet analysis depicted maximum relative energy on D6-D8 crystals, which represent large time scale events such as those occurring from localized attacks. Also, repassivation events too could be divulged from the potential EDP. The micrographs of the post electrochemical noise experimented specimens revealed the occurrence of localized attacks along the interdendritic region and none inside the dendritic cores. The presence of secondary phases along the interdendritic regions was found to be detrimental in chloride medium, imparting inferior localized corrosion resistance to the weld overlay.展开更多
文摘By adopting the alloy wire of Ni 80 Cr 20 as the welding core and adding the alloy elements of B, Si, Mo and W into the outer plating covering, a new type of wear resistant overlay welding rod of Ni Cr B Si was developed. This overlay welding rod has several properties such as low melting point and good fluidity. With low content of W and Mo, the wearability and crack resistance of the overlay welding rod can be increased, and the hardness can be increased to about HRC64. This kind of overlay rod has been applied to the overlay of wearable workpieces, such as the valves of high temperature, high pressure and the side plates of floor boarding brick die.
文摘Copper base alloy was overlaid onto 35CrMnSiA steel plate by tungsten inert gas （TIG） welding method. The heat transfer process was simulated, the microstructures of the copper base overlay were analyzed by scanning electron microscopy （SEM） and energy dispersive spectrometer （EDS）, and the friction and abrasion properties of the overlay were measured. The results show that the Fe content increases in the overlay with increasing the welding current. And with the increase of Fe content in the overlay, the friction coefficient increases and the wear mechanism changes from oxidation wear to abrasive wear and plough wear, which is related to the size and quantity of Fe grains in the overlay. While with the increase of Fe content in the overlay, the protection of oxidation layer against the oxidation wear on the melted metal decreases.
文摘The effects of chemical compositions and microstructures on wearability properties of overlaid corrugating roll were studied, and the factors governing the hardness and the wearability of overlaid layer were explored. The results show that the hardness and wearability of the overlaid layer significantly rise with the increase of the mass fraction of various types of eutectic, but the crack-resistance falls. The chief factor governing the hardness of overlaid layer is the matrix microstructure, especially the amount of austenite; and the second is the amount of carbide. The principal factor governing the wearability of overlaid layer is the amount of special carbide, particularly the amount of eutectic; and the second is the hardness of overlaid layer. Meanwhile, high alloying electrodes may cause the gear-surface hardness of corrugating roll to be higher than 63HRc, and may enhance the wearability of the gear-surface of corrugating roll by a factor of 5.63 and 9.08.
文摘The manuscript presents the results from the electrochemical noise (EN) monitoring of Inconel 82 weld overlay on Type 304L stainless steel (SS) weld in 0.01M FeCl3. The microstructure of the weld overlay obtained from optical and scanning electron microscopy (SEM) showed an austenite structure, containing equiaxed dendrites and secondary phases at the interdendritic region. Energy dispersive spectroscopy (EDS) attached to SEM revealed the secondary phases to be Nb rich Laves phase. The electrochemical potential noise was monitored using a three identical electrode configuration. The acquired signals were detrended, and wavelet analysis was employed to encode useful information from the noise transients. Visual examination of the potential noise-time record contained distinct high amplitude transients typical of localized corrosion attack. The energy distribution plots (EDP) of the potential noise derived from wavelet analysis depicted maximum relative energy on D6-D8 crystals, which represent large time scale events such as those occurring from localized attacks. Also, repassivation events too could be divulged from the potential EDP. The micrographs of the post electrochemical noise experimented specimens revealed the occurrence of localized attacks along the interdendritic region and none inside the dendritic cores. The presence of secondary phases along the interdendritic regions was found to be detrimental in chloride medium, imparting inferior localized corrosion resistance to the weld overlay.
