Stainless Steel and Nickel Heat Treating
The heat treating process involves controlled heating and cooling of solid metals and alloys in order to manipulate the final mechanical properties. Essentially, heat treating changes the molecular structure of the materials to make it either harder or softer.
- NSA’s Heat Treating Capabilities
- Vertical heat treating – up to 21’ long
- Horizontal heat treating – up to 40’ long
- Open fire water quench and temper – up to 12’ long
- Open fire oil quench and temper – up to 14’ long
- Normalize, age or stress relieve – up to 40’ long
- Carburizing or carbon nitriding – up to 48” long
- Gas nitriding – up to 96” long
- Vacuum processing – up to 72” long
Stress Relieving
Stress relieving is the process of heating materials to a suitable temperature and holding temperature long enough to reduce stresses (or internal stress that remains after the original cause of stress has been removed), followed by cooling the material slowly to minimize the development of new residual stresses. Stress relieving is not intended to change the microstructure or mechanical properties significantly, it is pure intended to allow steel to remain “stress-free” during the manufacturing process and throughout its life cycle.
Straightening
Straightening is the process of bending or bowing material using a hydraulic press in order to apply pressure at certain points and straighten any unwanted bent areas. There are a number of reasons for the straightening process to be completed. For instance, when material is delivered from the mill and does not meet proper commercial tolerance, or even after heat treatment of certain materials, it is necessary to straighten the material as sometimes it will bend outside the commercial tolerance.
- NSA’s Straightening Capabilities
- Commercial & precision straightening – from 1/8” over 5’ to .0015” per foot T.I.R. (total indicator run-out – measurable amount of allowable straightness deviation, or how far out of straightness the bar is).
Quench & Tempering
Quench and tempering in short is the process of changing austenite to martensite. This is carried out by heating steel within or above the suitable austinizing (or transforming) temperature range and holding it for a period of time in order to affect the desired change in grain structure. Next, the actual “quenching” takes place, cooling the material at a critical velocity by submerging it in a suitable liquid medium which imparts greater hardness and brittleness. To increase the stability, the material is then tempered at a certain temperature for a set period of time. In retrospect, quench and tempering is used to achieve hardness and mechanicals in the 400 Stainless Steel series of materials.
- Ex: used to acquire 410 Class 2, 410 Condition T and 416 Condition T
Unlike many other service centers NSA is committed to stocking processed material, making sure it is more readily available for our customers.
NSA’s Most Repeated/Stocking Capabilities
- Precipitation Hardened Grades and Exotics
- Age H900 – 1 hour heat treating
- Age H925 to H1150 – 4 hours of heat treating
- Age H1150D – two separate sets of heat treating, 4 hours each at 1150° F (also known as double H1150)
- Age H1150M – two separate sets of heat treating, first 4 hours at 1400° F second at 1150° F
(also known as H1150 Modified)
- 400 Stainless Steel Series
- Anneal for machining
- Harden and temper
- Additional temper or preheat
- NACE quench and double temper
- Harden and temper, straighten and stress relieve
- Support Processes
- Straightening (with heat treating 1/8” to 5’, and with heat treating 1/16” to 5’)
- 100% inspection (with heat treating)
- Load thermocouples
- Tensile testing
- Tensile and impact testing
- Certifications
- Chart (of each process)