Question

2. Iskandary Engineering Limited Sdn. Bhd. is making a proposal to manufacture flanges for aluminium pipes as shown in FIGURE Q2 by the most suitable casting method. As a production manager of the company, you are asked to write full proposal for manufacturing the flanges. The proposal should include but not limited to the following criteria and you have to justify each of the details: a. Suggest the best casting method. Justify your selection. [5 marks] b. Propose the materials to be used and its properties. [5 marks] c. Describe the process flow of casting process. [10 marks] d. Predict all the potential defects during casting. [15 marks] e. Suggest the inspection and measurement method after casting. [15 marks] FIGURE Q2

Answer 1

ANSWER:

(a) Flanges can be produced with different processes like forging, casting, cutting and also with rolling.

But here we are going to explain the process of casting for making and producing the casted flanges

In making of flange, we will use CENTRIFUGAL CASTING PROCES

Benefit of centrifugal casted flanges

• we can produce precise, shopisticated and exact shape and size
• Light weigh
• low cost of production

(b) Material used for casted flange is generally steel beacuse of its structural integrity and it can be of the given types:

• carbon steel
• mild steel
• alloy steel
• stainless steel

Properties of steel material for casted flanges:

• God durability
• good formability
• High tensile strength
• Low cost
• good thermal conductivity
• Corrosion resistance

(c) Process flow of casting process:

The process flow is as given below:

1. Picking the required raw steel material for flange and and putting in to the furnace for heating and taking the temperature of steel up to 1600-18800 degree centigrade
2. Now after heating and before putting it in centrifugal casting machine, the metal will be preheated between 800-1000 degree centigrade to maintain the temperature
3. After this turning the centrifugal casting machine and pouring of liquid steel in to the mold
4. Waiting for the temperature of steel material to fall down to 700-900 degree centigrade and than holding this temperature for 10 mins
5. After the time, water cooling of the mold and taking the temperature of steel to 25 degree centigrade and taking out from the mold

(d) Defects during the casting used in making flanges:

1. Hot tears:Due to uneven hoop stress in the region of solidus
2. Segregation
3. Banding: due to one of low melting points
4. blow holes
5. shrinkage porosity

(e) Inspection and mesurement method after casting:

1. Ultrasonic inspection and testing machine: work on vibration technoque