In the article An Investigation of the CaCO3CaF2 K2SiO3SiO2Fe Flux System Using the

Chapter 2, Problem 13

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In the article “An Investigation of the \(\mathrm{Ca}-\mathrm{CO}_{3}-\mathrm{CaF}_{2}-\mathrm{K}_{2} \mathrm{SiO}_{3}-\mathrm{SiO}_{2}-\mathrm{Fe}\) Flux System Using the Submerged Arc Welding Process on HSLA-100 and AISI-1018 Steels” (G. Fredrickson, M.S. thesis, Colorado School of Mines, 1992), the carbon equivalent P of a weld metal is defined to be a linear combination of the weight percentages of carbon \((\mathrm{C})\), manganese \((\mathrm{Mn})\), copper \((\mathrm{Cu})\), chromium \((\mathrm{Cr})\), silicon \((\mathrm{Si})\), nickel \((\mathrm{Ni})\), molybdenum \((\mathrm{Mo})\), vanadium \((\mathrm{V})\), and boron \((\mathrm{B})\). The carbon equivalent is given by

\(\mathrm{P}=\mathrm{C}+\frac{\mathrm{Mn}+\mathrm{Cu}+\mathrm{Cr}}{20}+\frac{\mathrm{Si}}{30}+\frac{\mathrm{Ni}}{60}+\frac{\mathrm{Mo}}{15}+\frac{\mathrm{V}}{10}+5 \mathrm{~B}\)

Means and standard deviations of the weight percents of these chemicals were estimated from measurements on 45 weld metals produced on HSLA-100 steel base metal. Assume the means and standard deviations \((\mathrm{SD})\) are as given in the following table.

a. Find the mean carbon equivalent of weld metals produced from HSLA-100 steel base metal.

b. Assuming the weight percents to be independent, find the standard deviation of the carbon equivalent of weld metals produced from HSLA-100 steel base metal.

Equation Transcription:

   

   

   

   

   

   

     

 

 

Text Transcription:

Ca-CO3-CaF2-K2SiO3-SiO2-Fe  

(C)  

(Mn)  

(Cu)  

(Cr)  

(Si)  

(Ni)    

(Mo)  

(V)  

(B)

P=C+Mn + Cu + Cr over 20 + Si over 30 +Ni over 60 + Mo over 15 + V over 10 + 5B

(SD)