Alloy Steel AISI 8630

 General Characteristics of AISI 8630 Stainless Steel

Alloy steel 8630 is a low-alloy steel containing nickel, chromium and molybdenum as alloying elements. The alloy has good hardenability, and good strength and toughness properties.

Chemical Analysis

 C%  Mn% P% S% Si% Ni% Cr%           Mo%
 0.28/0.33 0.70/0.90 0.040 max 0.040 max 0.20/0.35 0.40/0.70  0.40/0.60 0.15/0.25

Applications
This alloy finds oil patch applications as forged connectors, hangers and block valves.

Forging
This alloy is forged at a start temperature of around 2200ºF (1205ºC) and could be forged down to approximately 1700ºF(925ºC.) The alloy may be transferred to a furnace held at a temperature approximating the forging finishing temperature, soaked then air cooled.

Heat Treatment
Annealing: For optimum machinabilty of this alloy, a microstructure consisting of coarse pearlite and a minimum of ferrite is considered to be optimum. Such a structure can be obtained by austenitizing at 1550ºF (845ºC), furnace cooling to 1350ºF (730ºC) then to 1180ºF (640º) at 20ºF/hr. An alternative is an iso-anneal at 1225ºF (660ºC)

Normalizing: 1600ºF (870ºC) and air cool.
Hardening: The alloy will be austenitized at around 1525 – 1600ºF (830 – 870ºC) and oil or water quenched depending upon section size and intricacy.

Tempering: to desired hardness, using temperatures based on past experience, following water or oil quench.

Machinability: This grade of alloy is readily machined following suitable heat treatment.

Weldability: This steel may be welded by normal fusion methods, but prior to hardening and tempering. Pre heat and post heat may be necessary depending upon intricacy of part.