Effect of chemical composition on mechanical properties of A694 F65 steel flushing pressure cap forging of deep water pipeline connector

Aiming at the A694 F65 steel forging of flushing pressure cap for deep water pipeline connector,on the premise of meeting the standard requirements,two kinds of forged material scheme with different chemical compositions,namely alloying elements with slight changes were designed.The same forging and heat treatment process was used for processing and manufacturing,and the mechanical properties test and metallographic inspection of the two forging products were carried out.The results showed that while considering carbon equivalent to enswre weldability,the contents of carbon and manganese were reduced,and the contents of alloy elements such as chromium,nickel and molyblenum were increased,the micro structure of the forgings was the required bainite+ferrites.The nonmetallic inclusion content was low,and the material strength met the design requirements.The low-temperature impact toughness of the forgings met the product design requirements,and the test results of impact toughness at-46℃ and-18℃ were quite different.With the increase of test temperature,the impact toughness test results stability improved.