Alloy Steels with Tensile Strengths of 100,000 psi or Greater
Alloy steels with tensile strengths (or yield points) greater than 100,000 psi (689 MPa) have earned the designation Grade 100. These steels are available in multiple grades, based on chemical composition and mechanical properties. Each grade has a specific set of properties for strength, ductility, fatigue resistance, and so on that should be taken into account when selecting steel for any particular application.
The following is a list of some of the more commonly used alloy steels with tensile strengths of 100,000 psi or greater and their chemical composition (in percent by weight):
1. ASTM A514 Grade A – A low alloy steel with a yield point of 100 ksi (689 MPa) or greater. It’s primarily composed of 0.20-0.30% carbon; 0.50% manganese; 0.90-1.50% molybdenum; 0.90-1.50% chromium; 0.15-0.30% silicon; 0.08% max phosphorus; 0.030% max sulfur; 0.87-1.30% vanadium; 0.15-0.40% nickel; 0.12-0.50% cobalt.
2. ASTM A709 Grade 100 – A high-strength, low-alloy steel with yield point of 100 ksi (689 MPa). Its composition includes 0.10-0.20% carbon; 1.00% manganese; 0.50-1.20% chromium; 0.08-0.30% silicon; 0.025% max phosphorus; 0.030% max sulfur; 0.07-0.50% molybdenum; 0.12-0.40% nickel; 0.03-0.10% vanadium; 0.05-0.20% copper; 0.020% max titanium.
3. ASTM A841 Grade G – A high-strength, low-alloy steel with yield point of 100 ksi (689 MPa). It’s primarily composed of 0.20-0.25% carbon; 1.00% manganese; 0.50-1.20% chromium; 0.06-0.20% silicon; 0.120% max phosphorus; 0.030% max sulfur; 0.10-0.60% molybdenum; 0.060-0.20% nickel; 0.10-0.30% vanadium; 0.05-0.15% copper; 0.08-0.21% niobium; 0.030% max titanium; 0.003-0.012% boron.
4. ASTM A353 Grade G – A low alloy steel with yield point of 100 ksi (689 MPa). Its composition includes 0.30-0.40% carbon; 0.60-1.25% manganese; 0.45-0.60% chromium; 0.05-0.15% silicon; 0.115% max phosphorus; 0.020% max sulfur; 0.70-1.20% molybdenum; 0.12-0.20% nickel; 0.30-0.45% vanadium; 0.030% max titanium; 0.07-0.13% nitrogen; 0.010% max boron.
5. ASTM A517 Grade F – A high-strength, low-alloy steel with yield point of 100 ksi (689 MPa). Its composition includes 0.20-0.25% carbon; 1.00% manganese; 0.50-1.20% chromium; 0.06-0.20% silicon; 0.030% max phosphorus; 0.030% max sulfur; 0.07-0.50% molybdenum; 0.12-0.40% nickel; 0.03-0.10% vanadium; 0.060-0.20% copper; 0.15-0.40% niobium; 0.030% max titanium.
6. ASTM A441 Grade H – A high-strength, low-alloy steel with yield point of 100 ksi (689 MPa). Its composition includes 0.20-0.25% carbon; 0.50-1.30% manganese; 0.60-1.10% chromium; 0.06-0.15% silicon; 0.035% max phosphorus; 0.040% max sulfur; 0.30-0.60% molybdenum; 0.12-0.30% nickel; 0.50-1.00% vanadium; 0.020% max titanium; 0.010% max boron.
7. ASTM A620 Grade D – A low alloy steel with yield point of 100 ksi (689 MPa). Its composition includes 0.30-0.45% carbon; 1.00-1.50% manganese; 0.60-1.00% chromium; 0.08-0.17% silicon; 0.050% max phosphorus; 0.030% max sulfur; 0.07-0.55% molybdenum; 0.15-0.30% nickel; 0.03-0.07% vanadium; 0.030% max titanium.
By specifying one of these Grade 100 alloy steels, engineers can be assured of a durable and high-strength steel that meets their applications requirements. Further, by familiarizing themselves with all the grades available, they can select the best steel for a given application.
