What is "Stainless Steel"?

"Stainless" word is "Stain + Less". But actually it is resistant to rust, only.

Normally Stainless is steel that contained Chrome over 15%, classified Martensite, Ferrite and Austenite.(JIS G 2030)

Stainless is superior in corrosion resistance, because it has a passivation film hydrated oxy hydroxide on surface of steel. This passivation film is self repaired soon in oxidation atmosphere, when it has some damage. This is a structure of superior in corrosion resistance.Passivation films became strong by increasing Chrome and Nickel contain. And It will be stronger by component other elements (Mo, Cu, Si and etc) and suitable for many kinds of fluids.

Hisaka's ball valves are selected equivalency casting steel of Austenite SUS304, SUS316, SUS316L for stainless steel with our standard material.

SUS304 is contained Chrome 18% & Nickel 8%, generally called 18-8 Stainless Steel.
18-8 Stainless Steel is used for many kind application, for example: Petrochemical company.

SUS316 is stainless steel contained Chrome 18% & Nickel 12%, and added Molybdenum for increasing corrosion resistance.
SUS316 is superior for corrosion resistance, better than SUS304.

SUS316L is super low carbon steel content of carbon equal to below 0.03%, and improved performanceof SUS316. It has performance of SUS316 add with Interguranular Corrosion Resistance also.

SUS329J4L is super low carbon steel, which is a stainless steel with extremely excellent corrosion resistance that has been increased in Molybdenum and added with Nitrogen.

Special materials (Hastelloy, titanium, etc.)

Hastelloy is an alloy with high corrosion and heat resistance made by adding numerous additives such as molybdenum and chromium to a nickel base.
Hastelloy B, C, and other varieties are made by adding differing amounts of molybdenum, chromium, and other additives.
HISAKA WORKS can manufacture using Hastelloy C (equivalent to C276), Hastelloy B, and Hastelloy C22-equivalent materials.

Hastelloy C contains a high amount of molybdenum, and low amounts of carbon and silicon to provide excellent resistance to pitting, crevice corrosion, and similar defects.

Hastelloy B provides strong resistance to hydrochloric acid regardless of the temperature.

Hastelloy C22 provides excellent resistance to both oxidation and reduction, and is therefore used in conditions with repeated oxidation-reduction.

Use of titanium

Titanium is a material combining light weight with excellent strength.
Titanium can also prevent rust because the passive state film of the titanium surface does not permit oxygen to pass through it.
Titanium provides better corrosion resistance than stainless steel, and it has good corrosion resistance in general, especially against alkalinity and seawater.
The standard material used in ball valves of HISAKA WORKS is cast metal equivalent to Class 2 titanium.

JIS-ASME Standard Correspondence List