DEVELOPMENT OF 100 GRADE AND ABOVE MINING CIRCULAR LINK CHAINS
Based on the theory of diffusion type transformation and dispersion strengthening,0.23％and 0.39％W alloy elements were added to the steel to develop low carbon martensite mining circular link chain.The Gleeble testing machine and end hardening test were used to test the CCT curve and hardenability of new steel.OM,SEM and TEM were used to analyze the microstructure and mechanical properties of different heat treatment states.The breaking force and corrosion performance of mining circular link chain were tested by ring chain breaking test and salt spray test.The results show that compared with 23MnNiMoCr54 steel,the critical cooling rate for obtaining all martensite of the new steel is reduced to 5 ℃/s.The mixed structure of martensite and bainite is obtained within 5～0.3 ℃/s.The ferrite+pearlite structure is obtained below 0.3 ℃/s.The hardness at 25 mm was 45 HRC and didn't significantly decrease compared to 23MnNiMoCr54.With the increase of tempering temperature,the tensile strength decreases,and the impact toughness increases its maximum tensile strength of 1 350 MPa.The impact toughness is greater than 85 J.The industrial production of circular link chain has a breaking force of 120 grade level and a corrosion rate 1.46 g per day,meeting the performance requirements of large specification mining circular link chains of 100 levels and above according to GB/T12718.
circular link chain steelalloy elementhardenabilitytensile strengthcorrosionweldingfatigue
万方数据
维普
