Cast Steel Material Could Be Weld?

it can be, yes

https://www.youtube.com/watch?v=Yopcz-IYDyQ

It is possible for welding but definitely not recommended for strength concerns. Cast Iron/steel are brittle usually goes with high carbon content. Localized heat in the weld will result to residual stress on the spot and surrounding material, thus consequent to breaking and material fatigue when subject to external forces or pressure.

It is a bad idea. But, try welding sample cast iron and you will see how it is.

I used to 'upgrade' cast ss valve bodies used in submarine service, process was grind out imperfect areas, preheat, tig weld fill, post heat to stress relieve, pack in vermiculite for cool down (appx. 16 hrs).

The main problem encountered is that inexperienced welders have made a mess and the reputation of some metals has worsened. I have never had problems with this grade of steel either as cast or a forging. The correct weld procedures however must be followed as in any welding job. Keep the inexperienced welders away from it

Yes there are differents ,yes is true and yes this material could be welded.

Avatar Indo you have to check ASTM 216/216M "Specification for steel castings, carbon, Suitable for fusion welding for High temperature service"

An extract (ASTM SA 216/SA 216M):

Repair by Welding

10.1 Repairs shall be made using procedures and

welders qualified under ASME Section IX.

10.2 Weld repairs shall be inspected to the same

quality standards that are used to inspect the castings.

When castings are produced with Supplementary

Requirement S4 specified, weld repairs shall be inspected

by magnetic particle examination to the same standards

that are used to inspect the castings. When castings are

produced with Supplementary Requirement S5 specified,

weld repairs on castings that have leaked on hydrostatic

test, or on castings in which the depth of any cavity

prepared for repair welding exceeds 20% of the wall

thickness or 1 in. [25 mm], whichever is smaller, or on

castings in which any cavity prepared for welding is

greater than approximately 10 in.2 [65 cm2], shall be

radiographed to the same standards that are used to inspect

the castings.

10.3 Castings containing any repair weld that exceeds

20% of the wall thickness or 1 in. [25 mm], whichever

is smaller, or that exceeds approximately 10 in.2 [65

cm2] in area, or that was made to correct hydrostatic

test defects, shall be stress relieved or heat-treated after

welding. This mandatory stress relief or heat-treatment

shall be in accordance with the procedure qualification

used.

Copyright ASMERepair by Welding

10.1 Repairs shall be made using procedures and

welders qualified under ASME Section IX.

10.2 Weld repairs shall be inspected to the same

quality standards that are used to inspect the castings.

When castings are produced with Supplementary

Requirement S4 specified, weld repairs shall be inspected

by magnetic particle examination to the same standards

that are used to inspect the castings. When castings are

produced with Supplementary Requirement S5 specified,

weld repairs on castings that have leaked on hydrostatic

test, or on castings in which the depth of any cavity

prepared for repair welding exceeds 20% of the wall

thickness or 1 in. [25 mm], whichever is smaller, or on

castings in which any cavity prepared for welding is

greater than approximately 10 in.2 [65 cm2], shall be

radiographed to the same standards that are used to inspect

the castings.

10.3 Castings containing any repair weld that exceeds

20% of the wall thickness or 1 in. [25 mm], whichever

is smaller, or that exceeds approximately 10 in.2 [65

cm2] in area, or that was made to correct hydrostatic

test defects, shall be stress relieved or heat-treated after

welding. This mandatory stress relief or heat-treatment

shall be in accordance with the procedure qualification

used.

To determine the P and F numbers read

ASME IX

QW 420 and 430.

WP

It is interesting, since as far as I am aware, the larger bores use A216, due to the difficulties and the costs in forging large pieces. The forging scores over the casting due to only integrity (defect prone -pin hole etc and other casting defects) and no other technical reason I can think of.

Bad reputation of castings are due to,

1. Most of the casting standards are lenient in composition, heat treatment and inspection.

2. The control exercised by the foundries, due to lack of knowledge or economics, in both composition and heat treatments. Due to this the quality factor on general castings (derating factor) is specified in the ASME/VIII which with the proper NDE and testing could be again made 100%.

However since these additional NDE requirements are not mandatory (supplementary requirements) would be enforced only if specified in specific purchase orders. These (Radiography, LPI, MPI etc) ensures the structural rigidity.

But there is another factor which you must bear in mind. The forgings are usually two halves, joined by flange or welding. But castings are usually single piece.