Carrying out final inspection of castings
Overview
This standard identifies the competencies you need to carry out final inspection of castings produced from sand or ceramic moulds, dies or investment shells, in accordance with approved procedures. The inspection methods used will include both visual and dimensional methods and will involve the use of a range of measuring instruments, gauges, jigs and fixtures. You will be required to select the appropriate instruments and equipment to use, based on the type, size, alloy and inspection requirements of the castings. Both ferrous and non-ferrous castings are covered by this standard. You will ensure that the measuring equipment used is correctly calibrated and meets the necessary quality assurance procedures.
The castings inspected will be circular, square or irregular in shape and will have projections and internal cavities. The profiles will be curved and tapered. You will carry out the final inspection of the castings using component drawings, specifications and other information, such as non-destructive testing (NDT) reports and metal analysis results. You will visually and dimensionally inspect the external and internal features of the castings, as laid down by the specification. The inspection will generally take place after the castings have received a provisional visual examination and have been fettled.
You will use, where appropriate, workholding devices, benches and lifting equipment to manipulate the castings during the final inspection operation. There could be occasions when larger castings are sited on the floor and you will be expected to manoeuvre these, safely, to complete the work. You will be expected to mark up the castings to show where there are any deviations from drawings and specifications. Using all available information, you will make the decision as to which castings are within specification and will make a declaration to confirm this. Castings that fail to meet the specification will be scrapped, or will be treated in accordance with the company procedure for sub-standard castings. The completed inspection report, along with the casting, will be passed to the appropriate person, in accordance with procedures.
Your responsibilities will require you to comply with organisational policy and procedures for the casting final inspection activities undertaken and to report any problems with the measuring instruments, tools and gauges/jigs in use that you cannot personally resolve, or are outside your permitted authority, to the relevant people. You will be expected to work to with a minimum of supervision, taking personal responsibility for your actions and for the quality and accuracy of the work that you carry out.
Your underpinning knowledge will provide a good understanding of your work and will provide an informed approach to the final inspection of various types and size of castings using visual, metallurgical and measuring methods. You will understand the different instruments, gauges/jigs used and how to interpret information on metallurgical reports. The importance of compiling accurate and legible reports will be a key issue in complying with this standard.
You will understand the safety precautions required when carrying out the final inspection activities and when using the associated tools and equipment. You will be required to demonstrate safe working practices throughout and will understand the responsibility you owe to yourself and others in the workplace.
Performance criteria
You must be able to:
- work safely at all times, complying with health and safety legislation, regulations, directives and other relevant guidelines
- follow the correct specification/technique for the product or equipment being inspected
- identify and confirm the inspection checks to be made and acceptance criteria to be used
- carry out the inspections, using appropriate equipment and techniques
- identify any casting defects/flaws or variations from specification
- record the results of the inspections in the appropriate format
- deal promptly and effectively with problems within your control and report those that cannot be solved
- ensure that work records are completed, stored securely and available to others, as per organisational requirements
- leave the work area in a safe condition on completion of the activities, as per organisational and legal requirements
Knowledge and Understanding
You need to know and understand:
- the specific safety precautions to be taken whilst carrying out the activities (including any specific legislation, regulations or codes of practice relating to the activities, equipment or materials)
- the health and safety requirements of the work area and the activities, and the responsibility these requirements place on you
- the hazards associated with the activities, and how to minimise them and reduce risks
- the personal protective equipment and clothing (PPE) to be worn during the activities
- how to obtain the job instructions, specifications and drawings, and how to interpret the information
- why castings need to be finally inspected using a range of different methods
- the inspection equipment that is used for the final inspection activities
- how to check that the inspection equipment is within current calibration dates
- to the importance of keeping the inspection equipment clean and free from damage, good housekeeping of tools and equipment and to maintaining a clean and tidy working area
- how to carry out inspection checks of the castings (to include checking dimensions, flatness, squareness, straightness, angles and tapers, roundness and concentricity, centres of holes or bosses, and profiles)
- the defects/flaws or discontinuities in the castings caused by the moulding process and their effects on final inspection activities
- the level of defects/flaws that are acceptable in castings which are used for different purposes
- why some defects/flaws can only be determined using internal examination methods
- how to use and interpret information contained in metallurgical reports
- the system of quality control within the company and who is responsible for it
- the extent of your own responsibility and whom you should report to if you have problems that you cannot resolve
- how to access, use and maintain information to comply with organisational requirements and legislation
Scope/range
Scope Performance
Carry out final inspections of castings, carrying out all of the following activities:
- obtain the required inspection equipment and check it is correctly calibrated and in a safe and condition
- adhere to health and safety regulations, systems and procedures to realise a safe system of work
- comply with job instructions, final inspection specifications
- use the correct tools and equipment for the inspection activities
- follow the defined inspection procedures leave the work area in a safe condition on completion of the activities
Carry out final inspection of castings produced by one of the following processes:
- green sand
- ceramic materials
- chemically bonded gas activated sand
- investment castings
- chemically bonded resin activated sand
- die castings
- resin bonded heat activated sand
- evaporative pattern
- other process (specify)
Carry out final inspection of castings made from one of the following materials:
- ferrous alloys
- non-ferrous alloys
- non-metallic materials
Inspect castings for non-compliance, using two of the following methods:
- external visual
- metal structure
- metallurgical
- internal visual
- dimensional
Use measuring and marking out instruments, to include both of:
- micrometers
- verniers
and seven more of the following: - engineer's rule or tape
- protractors
- profile gauges
- height gauges
- callipers
- radius gauge
- straight edges
- dividers
- jigs or fixtures
- angle plates
- go/no-go gauges
- squares
- other specific instruments
Carry out dimensional checks on castings, to include six of the following features:
- flatness
- roundness
- angle
- squareness
- concentricity
- profiles
- straightness
- taper
- centres
Check, by dimensional inspection, eight of the following casting features:
- overall dimensional tolerances
- incorrect profiles
- sectional variances
- ovality in holes
- swells
- excessive flash
- misplaced cores
- hole centres out of tolerance
- cross joints
- thin or thick metal sections
- depth of inclusions on casting surfaces
- lack of metal on surfaces requiring machining
- loss of definition/size on machining location points
- other features (specify)
Follow the correct procedure to deal with castings in all of the following categories:
- castings which meet the specification
- castings requiring other inspection methods
- castings requiring further investigation
- scrap castings
Complete the inspection activities, carrying out all of the following:
- marking up defective castings with all relevant information
recording all the required details of the final inspection in the appropriate format
handing over the castings and inspection details to the appropriate people