Grade 630 stainless steels are martensitic stainless steels

Key Properties

The properties mentioned below pertain to commonly available grade 630 bar products in ASTM A564. The specifications may not be similar to other forms such as forgings and plates.

Composition

The compositional ranges of grade 630 stainless steels are displayed below:

Table 1. Composition ranges for grade 630 stainless steels

Grade		C	Mn	Si	P	S	Cr	Ni	Cu	Nb+Ta
630	min. max	- 0.07	- 1	- 1	- 0.04	- 0.030	15 17.5	3 5	3 5	0.15 0.45

Mechanical Properties

The table below outlines the mechanical properties of grade 630 stainless steels:

Table 2. Mechanical properties of grade 630 stainless steels

Condition	Tensile Strength (MPa)	Yield Strength 0.2% Proof (MPa)	Elongation (% in 50mm)	Hardness
				Rockwell C (HR C)	Brinell (HB)
Solution Treated	1105 typ	1000 typ	15 typ	38 max	363 max
Condition 900	1310 min	1170 min	10 min	40 min	388 min
Condition 1150	930 min	724 min	16 min	28 min	277 min

*These values are specified for ASTM A564 and they apply only to certain size ranges. The specification should be consulted for the complete details of these properties.
Condition 900 is aged at 900°F (482°C), Condition 1150 is aged at 1150°F (621°C).
Solution treatment is at 927°C and cooled as required.

Physical Properties

The physical properties of grade 630 stainless steels are given in the following table:

Table 3. Typical physical properties of grade 630 stainless steels

Grade	Density (kg/m3)	Elastic Modulus (GPa)	Mean Co-eff of Thermal Expansion (µm/m/°C)			Thermal Conductivity (W/m.K)		Specific Heat 0-100°C (J/kg.K)	Elec Resistivity (nΩ.m)
			0-100°C	0-315°C	0-538°C	At 100°C	At 500°C
630	7750	197	10.8	11.6	-	18.4	22.7	460	800

Grade Specification Comparison

The typical grade specifications of 630 stainless steels are tabulated below:

Table 4. Grade specifications for grade 630 stainless steels

Grade	UNS No	Old British		Euronorm		Swedish SS	Japanese JIS
		BS	En	No	Name
630	S17400	-	-	1.4542	X5CrNiCuNb16-4	-	SUS 630