Abdullah Ansari

EN-GJS-400-18-LT Castings for Cold Climate

Technical Feasibility AssessmentA T Ansari

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

Background – GL note for cold climate

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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 SCMCan cater to fluctuating market demandReduced casting weightLess chances of thread rip-off in castingFastener length can decrease

Project Team Abdullah Ansari Mr. Seenivasa Ragavan

Schedule Measure Analyze Improve Control

Jan-2014 Feb-2014 Apr-2014 Apr-2014

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.

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

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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Improve : Factor Analysis

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Main Effect by Impact testing temperatureOther 3 are interaction effects between 0.2% proof, Tensile, elongation & impact testing temperature

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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Control : Impact estimation at -40

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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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Impact data distribution

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-20 Calculated -40

Define – Close loop

Project Name Assessment of STV castings for LTV suitability

ObjectiveDevelop estimation tool for impact. Analysis of Impact data for tested castings of EN-GJS-400-LT

Benefits Flexibility to SCMCan cater to fluctuating market demandReduced casting weightLess chances of thread rip-off in castingFastener length can decrease

Project Team Abdullah Ansari Mr. Seenivasa Ragavan

Schedule Measure Analyze Improve Control

Abdullah Ansari

Thank You