ASTM A335(or ASME SA335) is the standard specification for seamless ferritic alloy steel pipe for high temperature service,it covers steel grades from P1 to P5,P9,P11,P12,P91.Grades P11/P22 and P91/92 pipes are commonly used in power industry and petro-chemical plants,while ASTM A335 grade P5 and P9 pipes are mostly used for application in the petrochemical industry.
ASTM A335 P91 seamless steel pipes ASME SA335 P91 alloy steel pipes
ASTM A335 P91 seamless alloy steel pipes-High pressure boiler pipes
ASTM A335 Grade P91 seamless alloy steel pipe is a good grade pipe applied for high pressure boiler,ans it is ideal when it comes to bending,flanging or when it is used in similar operations such as welding.The material of steel should stick to the composition of chemicals,tensile property and the requirements of hardness.
Specification of ASTM A335 P91 seamless alloy steel pipes:
| Size | 1/8″ – 24″ |
| Standards | ASTM A335,ASME SA 335 |
| Type | Seamless steel pipe |
| Specialized in | Large diameter size |
| Outer Dimensions | 19.05mm-114.3mm |
| Wall Thickness | 2.0mm-100mm |
| Length | 6 meters,12 meters or customized. |
| Schedule | Schedule 20-Schedule XXS(heavier on request) up to 250mm thick. |
| Form | Round,Square,Rectangular,Hydraulic etc. |
| Length | Single random length/Double random length or as customer’s actual request |
| Pipe End | Plain End,Beveled End,Threaded End. |
| Coating | Fusion bond epoxy coating,coal tar epoxy,3PE,varnish coating,bitumen coating,black oil coating as per customer’s requirement. |
| Package | Bags,bundles,PVC packing,carton packing,wooden case,or as customer request. |
Chemical Compositions(%) for ASTM A335 P91 seamless alloy steel pipes:
| Compositions | Data |
| Carbon(max.) | 0.08-0.12 |
| Manganese | 0.30-0.60 |
| Phosphorus(max.) | 0.020 |
| Sulphur(max.) | 0.010 |
| Silicon | 0.20-0.50 |
| Chromium | 8.00-9.50 |
| Molybdenum | 0.85-1.05 |
| Vanadium | 0.18-0.25 |
| Nitrogen | 0.03-0.07 |
| Nickel(max.) | 0.40 |
| Aluminum(max.) | 0.02 |
| Niobium | 0.06-0.10 |
| Titanium(max.) | 0.01 |
Mechanical properties for ASTM A335 P91 seamless alloy steel pipe:
| Properties | Data |
| Tensile strength, min, (MPa) | 585 Mpa |
| Yield strength, min, (MPa) | 415 Mpa |
| Elongation, min, (%), L/T | 30/20 |
ASTM A335 P91 seamless alloy steel pipe features:
A335 P91 not only has high oxidation resistance and high temperature steam corrosion resistance,but also has good impact toughness,stable durable plasticity and thermal strength.When the temperature is lower than 620℃,the allowable stress is higher than that of austenitic stainless steel.Above 550℃,the recommended design allowable stresses are approximately twice that of T9 and 2.25 cr-1mo steels.P91 alloy steel pipe is equivalent to national standard 10Cr9Mo1VNb.
A335 P91 alloy steel pipe can be used for subcritical and supercritical high temperature superheater and reheater steel pipe with wall temperature ≤625℃, as well as high temperature header and steam pipe with wall temperature ≤600℃,as well as nuclear power heat exchanger and oil cracking unit furnace pipe.
P91 steel is a new type of martensitic heat resistant steel,which reduces the carbon content on the basis of 9Cr1MoV steel,strictly limits the content of sulfur and phosphorus,and adds a small amount of vanadium and niobium for alloying.The steel number corresponding to P91 steel is X10CrMoVNNb91 in Germany,HCM95 in Japan and TUZ10CDVNb0901 in France.
ASTM A335 P91 seamless alloy steel pipe heat treatment process:
The final heat treatment of P91 is normalizing and tempering with high temperature, normalizing temperature is 1040℃, holding time is no less than 10 min, tempering temperature is 730 ~ 780℃, holding time is no less than 1h, and the final structure after heat treatment is tempered martensite.
Haihao Group manufacture piping products(steel pipes,butt welding pipe fittings,forged pipe fittings,flanges) more than 30 years,we produce the piping products in different standards such as ANSI/ASME,API,ASTM,BS,DIN,EN,GOST,ISO,JIS,MSS,UNI,etc.The materials can be carbon steel,stainless steel,alloy steel.If you want to know more about our piping products,please email us:sales@haihaogroup.com
