UNSN08825 alloy wear-resistant plate is a Ni-Cr-Fe corrosion-resistant high-temperature alloy with excellent oxidation resistance and corrosion resistance. It has good mechanical properties from room temperature to 550°C and is widely used in petroleum, chemical industry, power, food and other fields. . Some Ni-based corrosion-resistant high-temperature alloy wear-resistant plates such as UNSN06600, UNSN08825, and UNSN08535 can be made by hot extrusion or hot perforation. The alloy wear-resistant plate extruded by hot extrusion method reduces the yield rate due to factors such as end eccentricity, large extrusion removal margin, and the need to drill through holes in the bar blank.
In order to improve the yield rate of UNSN08825 nickel-based corrosion-resistant alloy wear-resistant plates, researchers used thermal perforation methods to carry out trial production research on UNSN08825 alloy wear-resistant plates. That is, under the same heating temperature and holding time, the effect of the smelting process of the bar blank (electric furnace and electroslag) on the formability of UNSN08825 alloy wear-resistant plate was studied. The effects of different heating temperatures and the same holding time on the hot-piercing formability of UNSN08825 alloy wear-resistant plate, and the effect of different holding times on the hot-piercing formability of UNSN08825 alloy wear-resistant plate under the same heating temperature conditions.
The UNSN08825 alloy wear-resistant plate test material is Φ100mm polished bar. The experimental steps are:
The first step is the preparation of hot punched blanks. First, the Φ100mm polished bar is cut into short pieces of Φ100mm×L required for the finished product in sections according to the cutting length, and then the surface defects are ground and finally centered.
The second step is the heating of the billet. First, the billet cut into short pieces Φ100mm×L is preheated for 2 hours in the inclined-bottom furnace; then heated, the heating temperature is controlled between 1030℃~1040℃, and kept for 40~50min; finally, soaking and soaking are performed before perforation. Temperature 1070℃～1090℃, keep warm for 15～20min.
The third step is thermal perforation. The heated blank is hot punched, and the perforation specifications are: (Φ105~Φ110)×(9~10)×L.
The fourth step is microstructure observation. Take samples of the well-perforated tube blanks and the over-burned tube blanks at the end of the hot-perforated tubes to observe the microstructure of the good tube blanks and over-burned tube blanks. The test analysis results are as follows:
(1) UNSN08825 alloy wear-resistant plate has high deformation resistance when the temperature is 1060°C and below, making it difficult to bite in and easy to get stuck; when the temperature is around 1080°C, the tube blank with good tail can be penetrated; when the temperature is 1100°C and above At this time, although the deformation resistance of the billet is further reduced, the tail of the inserted raw tube is prone to overheating, overburning or even severe overburning. Moreover, when the temperature is 1120°C and above, the burnt length of the unused tube has extended to the middle of the tube blank. It shows that when the temperature is above 1100°C, the thermoplasticity of the material decreases. Therefore, in order to ensure that UNSN08825 raw pipes with good quality are penetrated, the heating temperature should be controlled at around 1080°C, that is, 1070°C to 1090°C is optimal. In this temperature range, the material has lower deformation resistance and better thermal processing plasticity.
(2) In order to produce UNSN08825 hot-rolled alloy wear-resistant plates with good quality, the heat preservation time of the pipe blank in the soaking section is preferably controlled at 0.10~0.25min/mm.
