MASOUD ASTM A 316 L Modified - Urea Grade - has been specifically developed for Urea plant applications. It is a 316 L modified S.S with extra low carbon (C- Max: 0.03%) with extra low silicon (Si- Max: 0.50%) and substantial higher Molybdenum content (Mo: aroudn 2.5 to 2.7%). Cr is usally 18% in this 316 L modified Urea grade. Mn- usually 1to 2% but usally controlled to around 1.6-1.7% in 316 L Modified grade. The low carbon ctoent with well balanced chemistry (low silicon and Ni contetn close to 14%) makes the alloy fully austenitic. It is free of intermetallic phase precipitations. The ferrite level is kept under 0.5% in the solution annealed and water quenched conditions. The alloy is designed for improved corrosion resistance for Urea Carbamate or Ammonium Carbamate - both are highly corrosive and s.s erodes faster when let down takes place from Urea reactor to downstream exchangers and absorbers in any Urea operation. S.S 316 L is a general austenitic grade with ranges of cr, Ni. carbon can be 0.03-0.05% (depends on grades and manufacture), higher si, NMn optimum etc. Trust this answers your querry C.V.Srinivasan Nishi Engineers Pvt Ltd Chennai India April 22 E-mail:nishi@vsnl.com >I would like to know the difference between s.s 316L Urea >Grade and s.s 316L.What is difference between their >composition and their corrosion rate in urea services. >masoud