Mechanical properties of stainless steel QN1906Mo at sub-zero temperatures: Tests and stress-strain models

This paper made efforts on investigating low-temperature mechanical properties of new constructional stainless steel (SS) QN1906Mo. Forty-two tensile coupons were firstly tensioned at four low temperatures of 30,-30,-60, and-80 C. Environment for testing low temperatures was realized through an insulation chamber with injecting LNG. The test results reported low-temperature mechanical properties of SS QN1906Mo materials and welds. Test results showed that decreasing the temperature from 30 to-80 C did not affect the ductility and elastic Young's modulus of SS QN1906Mo material, but significantly increased yield and ultimate strengths of SS QN1906Mo material by 37% and 35%. Decreasing the temperature from 30 to-80 C also exhibited equivalent increments in yield or ultimate for weld coupons to those material coupons but with much larger scatters due to the air voids in the weld coupons. Finally, this paper developed constitutive models to describe stress-strain laws of SS QN1906Mo at varying T range of-80 & SIM;30 C, which were proved their capabilities.