IS 2490 : 2018Steel Castings for General Engineering Purposes

IS 2490:2018 is the specification for carbon and low-alloy steel castings for general engineering purposes — the grades, chemistry, mechanical properties, heat-treatment and testing of cast (not rolled/forged) steel components: bearing blocks, brackets, housings, machine and structural fittings, and shaped parts not economically forged.

It sits in the steel-materials stack:

• IS 1030 — carbon steel castings for general engineering (the closely-related casting spec) · IS 1865 — ductile-iron castings · IS 210 — grey-iron castings
• IS 1587 — Brinell hardness (casting screening) · IS 1608 Part 1 — tensile test · IS 2062 — wrought structural steel

Cast steel is shaped by pouring into a mould, which gives geometric freedom but a different metallurgy and defect set from rolled/forged steel:

• Grades by mechanical properties (tensile/yield/elongation) achieved via composition + heat treatment (annealing/normalising/quench-temper) — heat treatment is integral, not optional, to a casting meeting its grade
• Casting defects — porosity, shrinkage cavities, inclusions, segregation — are the characteristic risk; soundness verification (visual + NDT: radiography/ultrasonic, dye-penetrant) for important castings is essential
• Properties can be less uniform and direction-dependent than wrought steel; section thickness affects cooling and hence properties

The engineering point: a casting is accepted on **grade (heat-treated mechanical properties) *and* soundness (defect freedom) — not chemistry alone. The recurring failure is treating a casting like wrought steel and skipping NDT: an internally porous/shrinkage-flawed casting can meet a coupon tensile yet fail in service from a hidden cavity. Specify the grade, the heat-treatment condition, and** the NDT/acceptance level for the criticality.

Scenario: a load-bearing cast steel component (bracket/housing/fitting).

Step 1 — grade & heat treatment: select the IS 2490 grade for the required mechanical properties and specify the heat-treatment condition (the grade is only met heat-treated).

Step 2 — soundness/NDT level: for a load-bearing/critical casting, specify NDT (radiography/UT, dye-penetrant) and an acceptance level — soundness is part of acceptance, not optional.

Step 3 — test coupons + location: mechanical tests (IS 1608) on representative coupons; Brinell (IS 1587) for heat-treatment screening; note section-thickness effects.

Step 4 — accept on grade + soundness: both the property *and* the defect criteria — a porous casting that passes a coupon can still fail from a hidden cavity.

Step 5 — repair control: weld repairs of castings need a controlled, qualified procedure.

Grade + heat treatment + NDT together deliver a casting that performs; chemistry/coupon alone hides the cavity that fails it.

1. Accepting on chemistry/coupon alone. Castings need soundness (NDT) acceptance — a hidden shrinkage/porosity defect fails service despite a passing coupon.

2. Ignoring heat treatment. The grade's mechanical properties are only achieved in the specified heat-treated condition.

3. Treating castings like wrought steel. Different defect set, less uniform/directional properties, section-thickness sensitivity.

4. No NDT level for critical castings. Specify radiography/UT/dye-penetrant and an acceptance class by criticality.

5. Uncontrolled weld repair. Casting repairs need a qualified procedure — ad-hoc repair re-introduces defects.

• IS 1030 — carbon steel castings (closely related) · IS 1865 — ductile-iron castings · IS 210 — grey-iron castings
• IS 1608 Part 1 — tensile test · IS 1587 — Brinell hardness (heat-treatment screening)
• IS 2062 — wrought structural steel (the comparator) · IS 1757 — Charpy impact (toughness where required)

IS 2490 is current (2018) and the essential practitioner lesson is that a steel casting is not wrought steel: it offers geometric freedom but carries a characteristic defect set — porosity, shrinkage cavities, segregation — and its grade properties depend on heat treatment being integral, not optional. The chronic, dangerous error is accepting castings on chemistry or a single coupon and skipping soundness verification: an internally flawed casting can pass a tensile coupon and still fail in service from a hidden cavity. Specify the grade + heat-treatment condition + an NDT/acceptance level appropriate to criticality, screen heat treatment with Brinell (IS 1587), confirm properties by tensile (IS 1608), and control any weld repair with a qualified procedure. Castings accepted on grade *and* soundness perform; castings accepted on paper chemistry hide the defect that fails them.