Technical feasibility and risk assessment to use EN-GJS-400-18-LT in cold climates of -40 deg C

1. EN-GJS-400-18-LT Castings for
Cold Climate
Technical Feasibility Assessment
A T Ansari

2. Business Case
• Current specification different for standard temperature EN-GJS-400-18-LT
& low temperature versions EN-GJS-350-22-LT
• Two different specification take out flexibility from SCM and create a
bottle neck for casting supply when sudden change in market demand
• Easiest way is to have EN-GJS-350-22-LT castings common for both
climates
– This comes with side effects as tensile is less & castings have to be designed with
more weight.
– Thread engagements need to designed with bigger lengths
– Fastener lengths increases
• Another option is to have EN-GJS-400-18-LT material common for both
version with mandatory test of LTV qualifying
– This technical acceptable to certification
– From EN-1563 Casting standard point of view looks difficult
– Technical feasibility assessment with available data will help to conclude

3. Background – GL note for cold climate
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4. Define
Project Name Assessment of STV castings for LTV suitability
Objective Develop estimation tool for impact.
Analysis of Impact data for tested castings of EN-GJS-400-LT
Benefits Flexibility to SCM
Can cater to fluctuating market demand
Reduced casting weight
Less chances of thread rip-off in casting
Fastener length can decrease
Project Team Abdullah Ansari Mr. Seenivasa Ragavan
Schedule Measure Analyze Improve Control
Jan-2014 Feb-2014 Apr-2014 Apr-2014

5. Define : Test Program
• Planned Actions
– Identify casting manufactured for STV grade with normal process
control
– Conduct normal testing for STV
– Conduct additional impact test for LTV
– Wherever possible test impact at various temperatures
• 25, 0, -10, -20, -30 & -40
– Record the data for analysis.

6. Measure: Test Data
• Select supplier
• Test data collected
– Tested 85 castings
– 35 castings tested impact at -20 as well as -40
– 42 Castings tested at -20
– 8 Castings Tested at 25, 0, -10, -20, -30, & -40
• Results compiled for
– Tensile strength
– 0.2% proof strength
– Elongation
– Impact

7. Analyze: Relationship
• Regression analysis
– 160 results analyzed in 3 steps
– After removing 18 unusual reading, regression equation concluded
• Impact Avg = 50.5 + 0.220 Impact temp - 0.0661 0.2% YS(N/mm²) - 0.0422
TS(N/mm²) - 0.0646 % EL
• S = 1.36798 R-Sq = 83.5% R-Sq(adj) = 83.1%
• Analysis shows impac testing temperature & 0.2% proof strength are most
significant predictor for impact value
• R-Sq suggests that about 83% variation is captured
• Conduct Factor analysis for filtered data of 142 tests to find
out contributing factors sequentially
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8. Improve : Factor Analysis
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Main Effect by Impact testing temperature
Other 3 are interaction effects between 0.2% proof, Tensile, elongation & impact testing
temperature

9. Control : Calculate Impact at -40
• Filtered data of 80 castings which are tested at -20
• Estimate impact value at -40 temperature for those 80 casting
• Calculation results
– As per calculation only 6 castings qualify for impact at -40 for Avg 10J
– As per Calculation other 71 casting qualify for impact at -40 for indv 7J
– As per calculation rest 3 castings failed for even individual 7J but the
estimated value is more than 6J
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10. Control : Impact estimation at -40
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11. Technical Feasibility Assessment - Remarks
• Feasibility comments
– EN-GJS-400-18-LT to pass for impact 10J Avg at -40 deg C is difficult
– EN-GJS-400-18-LT to pass for impact 7J Indv at -40 deg C is very much
possible
• Input to Design
– Design assessment to be done with 7J & related factor of safety.
– If 7J average is acceptable, then with material EN-GJS-400-18-LT we can
move ahead
– If 10J mandatory requirement then for material EN-GJS-350-22-LT we
may need to go back
– Though GL guideline gives us option to choose EN-GJS-400-18-LT based
on pearlite content but it will be risky for fatigue life if required impact
value not achieved.
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12. Impact data distribution
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-20 Calculated -40

13. Define – Close loop
Project Name Assessment of STV castings for LTV suitability
Objective
Develop estimation tool for impact. 
Analysis of Impact data for tested castings of EN-GJS-400-LT 
Benefits Flexibility to SCM
Can cater to fluctuating market demand
Reduced casting weight
Less chances of thread rip-off in casting
Fastener length can decrease
Project Team Abdullah Ansari Mr. Seenivasa Ragavan
Schedule Measure Analyze Improve Control

14. Thank You