NAS STAINLESS STEEL STRIP MFG. CO., LTD.

Stands for stress relief. This heat treatment is generally used to remove residual stress.

Stands for tension annealing. This type of stress relief heat treatment applies tensile force to correct shapes.

The etching process chemically or electrochemically removes unnecessary portions of conductor on an insulating substrate to create a conductor pattern. A technique to expose the steel layer below the surface or to color steel using an appropriate corrosive liquid. A method for melting the surface of an item chemically or electrochemically to expose the layer below the surface. Masking (partial covering of surface) is sometimes used to cover certain areas of an item. An alkali or similar solution is used to dissolve unmasked areas and to create the desired pattern.

Austenite is gamma iron with solid carbon solution obtained by heating steel to temperatures above the A1 transformation point. Austenite crystals have a face-centered cubic structure. Austenite is nonmagnetic and has high electric resistance. In carbon steel, the content of the solid solution of carbon can be up to 2.03% at a temperature of 1,145℃ Although rapid cooling of carbon steel alone will not achieve a single phase austenite structure at room temperature, single phase austenite can readily emerge at room temperature in the presence of large amounts of manganese (Mn) and nickel (Ni). (Kinzoku Zairyo Gijutsu Yougo Jiten [Dictionary of Metal Terminology])

Austenitic stainless steel is stainless steel with a Cr-Ni based austenite structure. Type 304 and Type 316 are representative austenitic stainless steels. Austenitic stainless steel is corrosion resistant and easily formed, processed, and welded. Due to these characteristics, austenitic stainless steel is widely used in equipment

A gasket is a mechanical seal used on stationary surfaces to prevent fluid leaks, installed to prevent fluid leaks from pipe coupling flange surfaces, pump casing mating faces, and other joints.

Sub-zero treatment is heat treatment performed after hardening to transform residual austenite to martensite. This treatment reduces temperatures below room temperature to achieve soaking. Also referred to as deep cooling.

Containing more Cr and Mo than Type 304 and Type 316, super stainless steels contain 20% or more Cr and 5% to 6% or more Mo. Corrosion resistance is on par with Ni-based high corrosion resistant superalloys. Austenite structure super stainless steels containing 0.2% or more N and 18% or more Ni in addition to Cr and Mo are called super austenite stainless steels.

Cold rolled stainless steel undergoes work hardening and gains spring characteristics. Type 301 and Type 304, metastable austenitic stainless steels widely used as a stainless steel spring material, harden during cold rolling due to the formation of strain-induced martensite. SUS631 gains more stable spring characteristics when subjected to aging after work hardening.

Nickel based superalloys are nickel based alloys with Ni content of 50% or more. Nickel based superalloys offer corrosion resistance and heat resistance significantly superior to general purpose stainless steels.

Ferrite stainless steels are Fe-Cr based ferrite structure stainless steels, such as Type 430. Ferrite stainless steel is magnetic. Compared to austenitic stainless steel, ferrite stainless steel generally does not undergo work hardening as readily and tends to offer inferior characteristics. However, certain grades of ferrite stainless steel exhibit characteristics rivaling those of austenitic stainless steel.

Fe-Cr based martensite structure stainless steels such as 13Cr are highly magnetic and offer excellent hardenability.They are used to produce blades and other edged tools. Martensitic stainless steels are hard and brittle; workability, weldability, and corrosion resistance are inferior to those of austenitic stainless steels.

Stress relief annealing is an annealing process performed to maintain steel at appropriate temperatures below the transformation temperature to remove the residual stress induced by forging, casting, mechanical processing, or welding.

During plastic working of metal at temperatures below the recovery or recrystallization temperature, the force required for processing increases sharply with the amount of processing performed. The hardness and strength of the metal also increases, a phenomenon known as work hardening or strain hardening. The effect is attributable to the greater numbers of dislocations within the crystal structure, which results in intricate entanglements that prevent easy movement. (Kinzoku Zairyo Gijutsu Yougo Jiten [Dictionary of Metal Terminology])

Processing manganese steel or metastable stainless steel increases the Ms point and promotes martensitic transformation, a phenomenon known as work induced transformation. The Ms point can rise only to a certain point during processing; this upper limit is called the Md point. The extent of the transformation is greater with more processing and lower processing temperatures. Stainless steel that undergoes stain induced transformation is significantly stronger, but at the expense of toughness and ductility. (Kinzoku Zairyo Gijutsu Yougo Jiten [Dictionary of Metal Terminology])

Free cutting stainless steel refers to stainless steel whose machinability is improved by adding small amounts of phosphorus, sulfur, or selenium.

The crystal grain size, or the size of crystal grains in a polycrystalline material, is generally expressed as a grain size number obtained by the comparison method or interception method. The test used to determine austenite crystal grain size is specified in JIS G0551.

Residual stress refers to internal stress present in the absence of external forces or thermal gradients. Residual stress is induced by uneven deformations generated by cold working, quenching, welding, or other processes. The resultant force of external forces, thermal stress via differences in cooling speed, and transformation stress helps balance tensile residual stress and compressive residual stress within the material; however, this can lead to complex, uneven stress distributions that significantly affect mechanical characteristics

Aging is a phenomenon involving changes in the properties such as hardness of a metal or alloy over time after rapid cooling or cold working.It can also refer to the process that induces this phenomenon. There are two aging methods: natural aging at room temperature and accelerated aging by heating to a temperature above room temperature. Precipitation hardening stainless steel, Type 631, is generally treated at 475±10℃ for one hour (CH treatment) to adjust its properties.

Age hardening is a phenomenon whereby hardness increases over time when a supersaturated solid solution is maintained at temperatures below the solid solubility curve. Caused by precipitation from the supersaturated solid solution, this phenomenon is observed with many alloys.

Deep drawing is a press-forming method that applies a punch and a die to produce a container with a bottom plate from a flat sheet. This is done by pressing the punch against the sheet. Stainless steel used for deep drawing must have high austenite stability, excellent ductility, and minimal anisotropy.

Precipitation hardening stainless steel is made by adding small amounts of Al, Cu, Mo, or Ti to Cr-Ni based stainless steel and applying heat treatment to precipitate an intermetallic compound or solid solution, thereby achieving hardening.

The multi-stage drawing method involves multiple drawing processes used to form products of complex shapes, long cylindrical products, or other shapes difficult to form in a single pressing operation. Stainless steels used for multi-stage drawing must be soft and offer lesser work hardenability (e.g., NAS304LG).

A Fe-Ni alloy is an alloy made of iron and nickel. It may contain small amounts of Cr or Mn. Fe-Ni alloys have low/high thermal expansion coefficients and are used for various parts in electronic equipment, including shadow masks for cathode-ray tubes, IC lead frames, bimetals, and magnetic shields.

Duplex stainless steels are stainless steel materials characterized by a mixture of ferrite and austenite structures. They offer the characteristics of both ferrite and austenite. Duplex stainless steels offer excellent strength and toughness, as well as high resistance to corrosion and corrosion induced defects, such as grain boundary corrosion and stress corrosion cracking.

Austenitic stainless steel is nonmagnetic when it is subjected to solution heat treatment. However, as in the case of SUS304, cold working such as bending or drawing confers magnetic properties at the sections processed, due to the transformation to the work induced martensitic phase. Higher Ni content is associated with weaker magnetic fields. NASNM15M (with high Mn content) remains nonmagnetic, even when subjected to extensive cold working.

Nonmagnetic materials lack strong magnetic fields and have a specific magnetic permeability (?0) of roughly 1. Austenitic stainless steels and titanium alloys are nonmagnetic.