TP304H Stainless Steel Pipes & Tubes

Material Description UNS S30409 EN Number 1.4948 Chemical Composition, % C Mn P S Si Cr Ni .04-.10 2.0 .045 .03 1.0 18.0-20.0 8.0-11.0 TP304H is Austenitic Cr-Ni stainless steel. Better corrosion resistance than TP302. High ductility, excellent drawing, forming, and spinning properties. Essentially non-magnetic, becomes slightly magnetic when cold worked. Low carbon content means less carbide precipitation in the heat-affected zone during welding and a lower susceptibility to intergranular corrosion. Corrosion Resistance ● Organic acids at moderate temperatures ● Salt solutions, e.g. sulphates, sulphides and sulphites.

The risk of general corrosion in sulphuric acid during shut down periods has to be taken into account. Since TP304H is not alloyed with molybdenum, the grade can only tolerate low concentrations at limited temperatures. In naturally aerated sulphuric acid the corrosion rate is below 0.1 mm/year provided the temperature is not higher than 20°C (68oF) in 5% solution.

TP304H has a relatively high carbon content. Thus, there is a certain risk of reduced intergranular corrosion resistance if the steel has become sensitised after e.g. improper heat treatment or welding.

The steel may be sensitive to pitting and crevice corrosion even in solutions of relatively low chloride content. Molybdenum alloyed steels have better resistance and the resistance improves with increasing molybdenum content.

Austenitic steel is susceptible to stress corrosion cracking. This may occur at temperatures above about 60°C (140°F) if the steel is subjected to tensile stresses and at the same time comes into contact with certain solutions, particularly those containing chlorides. Such service conditions should therefore be avoided. Conditions when plants are shut down must also be considered, as the condensates which are then formed can develop conditions that lead to both stress corrosion cracking and pitting.

Application

Heat exchanger tubing, condenser tubing, pipelines, cooling and heating coils in the chemical, petrochemical, fertiliser, pulp and paper and nuclear power industries, as well as in the production of pharmaceuticals, foods and beverages.

Seamless Tube Information

Specification: ASTM A-213 / ASME SA-213, ASTM A312 / ASME SA312, EN10216-5

Outside Diameter: 6.0-406 mm (1/4’’ – 16’’)

Wall Thickness: 0.5-35 mm (0.0196’’ – 1.378’’)

Length: Max.33000 mm (the maximum length is for the scope of special diameters and walls)

Other sizes are on the request