Low-carbon steel is being replaced by HSLA steels in automobiles to save weight because the higher...

 

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Low-carbon steel is being replaced by HSLA steels in automobiles to save weight because the higher strengths of HSLA steels permit use of thinner gauges. In laboratory tests at a strain rate of about 10-3s-, one grade of HSLA steel has a yield strength of 420 MPa with a strain-rate exponent of m = 0.005 while for the low-carbon steel, Y= 240 MPa and m = 0.015. Calculate the percent weight saving possible for the same panel strength assuming a) a strain rate of 10-3 s-', b) crash conditions with a strain rate of 10+4 s-'. Low-carbon steel is being replaced by HSLA steels in automobiles to save weight because the higher strengths of HSLA steels permit use of thinner gauges. In laboratory tests at a strain rate of about 10-3s-, one grade of HSLA steel has a yield strength of 420 MPa with a strain-rate exponent of m = 0.005 while for the low-carbon steel, Y= 240 MPa and m = 0.015. Calculate the percent weight saving possible for the same panel strength assuming a) a strain rate of 10-3 s-', b) crash conditions with a strain rate of 10+4 s-'.