Industrial application analysis and key parameter control of high manganese steel

1 Overview

High-manganese steel products can obtain good application results under actual working conditions. The key is to achieve the best matching of various parameters through process measures. For many years, we have been committed to research work in this area, through a large number of industries. Sexual test and statistical analysis of the results, summed up a set of scientific methods for the production of high manganese steel products, to ensure that high manganese steel products in good working conditions to obtain good application results. The key control parameters are now described below for peer reference.

2. Analysis of industrial application results of high manganese steel

Tables 1 and 2 show the production statistics of high manganese steel liner used in our concentrator.

According to the analysis of a series of statistical data, the average usage time of the ball mill liner of Baihualing Concentrator increased from 4128.84h in 2012 to 4892.27h in 2013, and the average service life of high manganese steel liner was extended by 767.43h. ZGMn13Cr2 was applied to the crushing machine's rolling wall and broken wall. The product was tested in the Baihualing Concentrator and a metallurgical machinery factory. The tested rolling wall was operated for 170 days and the broken wall was operated for 154 days. The rolled wall runs for 30 more days than the comparative product. The electric shovel bucket teeth consumed 450 pieces in the open pit mine in 2012. In 2013, the consumption was reduced to 300 pieces, and the wear resistance was also improved. In terms of the reliability of the use of high-manganese steel products, there is no breakage in the use of ball mill liners, grid plates, electric shovel teeth, etc., which contributes to the safe operation of the company's mining equipment and the improvement of equipment operation rate. The high-manganese steel products of the machine repair factory occupied the internal market of the company with high quality and gradually expanded to the external market.

3. Key parameter control

(1) High manganese steel composition control wC=1.0%～1.2%, wSi=0.35%～0.45%, wMn=11%～13%, wCr=1.5%～2.5%, wP=0.055%～0.075%, wS< 0.05%.

(2) The index σb≥680MPa, aK≥150J/cm2, hardness ≤229HBW, grain size≥2, inclusions≤4.

(3) The key parameters of the smelting process are Mn/C≥10, wP≤0.075%, the tapping temperature is 1520～1550°C, the baggating time is ≥5min, the pouring temperature is 1370～1420°C, and the cup sample in front of the furnace shrinks well.

Table 1 Statistics on the use time of the liner of Baihualing Concentrator in 2012

Table 2 Statistics of the use time of the liner of Baihualing Concentrator in 2013

(4) The metamorphism treatment adopts the composite modification process of 1# rare earth and aluminum in the package, and the amount of molten steel per ton is: 1# rare earth 1.5kg, aluminum ingot 1kg.

(5) Process simulation Through the solidification simulation of high manganese steel, under the condition of lost foam casting process, the outer cold iron should be placed in the 8 hot joints on the inner side of the rolling wall.

(6) The key parameters of the heat treatment process control the austenitizing temperature 1100～1150°C, the holding time ≥6h, and the quenching tank is stirred by high-pressure air to increase the cooling capacity of water. Castings with uneven wall thickness such as grid plates need to be slowly cooled in the mold for more than 48 hours before entering the heat treatment process, and the heating rate is ≤80 °C/h before the heating temperature of the casting reaches 760 °C.

(7) Alloying high-manganese steel castings used in low-impact conditions such as rolling walls and broken walls, alloyed with Cr, and the content is controlled at wCr=1.5% to 2.5%.

About the author: Cui Linke, Dong Jianjun, Li Zhixiang, Shaanxi Huaxian Jinduicheng Molybdenum Industry Group Co., Ltd. Machine Repair Factory.