Study on steel for medium carbon high strength anc

Research on steel for medium carbon high strength bolt

bolt is a rod anchored in coal and rock mass to maintain the stability of surrounding rock. Compared with other supports, it is an active support form, which has the advantages of simple support technology, good support effect, low material consumption and support cost, convenient transportation and construction, etc

with the continuous exploitation of coal resources, the mining depth of silicon is deepening. At present, the average mining depth of coal seams in China's coal mines is deepened by 9m every year. There are more than 50 mines with a mining depth of more than 700m, and 53% of China's total coal resources are buried deeper than 1000 m. Due to the high ground stress, high rock burst and large rheology of surrounding rock caused by deep mining, it has caused serious difficulties to the bolt support of coal roadway. It can be predicted that the demand for high strength and high bearing capacity anchor rods will be increasing

therefore, we hope to ensure that δ Under the premise of 5 ≥ 15%, the bolt of coal roadway has higher strength（ σ s≥1000～1200MPa， σ B ≥ 1200 ~ 1400MPa), at the same time, this kind of ultra-high strength bolt must be cheap and easy to be strengthened and toughened by heat treatment. The strength and plasticity of high-strength steel are often contradictory. Increasing the strength will lead to the decrease of plasticity; The strength of steel with good plasticity is not high. From the current research and development, transformation induced plasticity (trip) is a strengthening and toughening method that can improve the strength and plasticity of steel at the same time

the valve and oil circuit will be blocked and the machine may vibrate

the anchor bolt is a member working under the creep condition of rock, and its plastic deformation occurs in the range of low strain rate. Some researchers have studied the dependence of flow stress on deformation speed, and believe that the selection of steel for anchor bolts should be based on Quenched and tempered low alloy steel, followed by hot-rolled low alloy steel, and the strength reduction of ordinary low carbon steel is the most obvious. Accordingly, we conducted the following experimental studies

test method

in this test, the carbon containing Inner Mongolia graphene Materials Research Institute of low alloy Si Mn TRIP steel was officially established, and the medium carbon was selected as the amount, and the average content of 0.4% C-2% Si, Mn low alloy steel was selected as the test steel

the steel used for the test is melted in 100kg medium frequency furnace and forged after ingot casting