Nitrogen cannot be used for ferrous and nickel based alloys in hydrogen removal technique because_____(a) it leads to form high dross in metal castings(b) it gives rise to porosity in metal castings(c) it affects the grain size(d) it generates blow holes in metal castingsThe question was asked during an interview.This interesting question is from Gases in Metals topic in chapter Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I

Nitrogen cannot be used for ferrous and nickel based alloys in hydroge

1.	Nitrogen cannot be used for ferrous and nickel based alloys in hydrogen removal technique because_____(a) it leads to form high dross in metal castings(b) it gives rise to porosity in metal castings(c) it affects the grain size(d) it generates blow holes in metal castingsThe question was asked during an interview.This interesting question is from Gases in Metals topic in chapter Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I
Answer» Correct choice is (c) it affects the grain size For explanation: For ferrous and NICKEL based alloys, nitrogen cannot be USED because it is soluble in these and ALSO it MAY form nitrides which affect the grain size; therefore, in ferrous alloys in particular, accurate control of the nitrogen is necessary. In such situations, carbon monoxide BUBBLES are used.

Discussion

No Comment Found

Related InterviewSolutions

Which of the following is not desirable in casting design for minimum stress concentration?(a) Roundness of external corners(b) Local metal accumulations(c) No abrupt changes in casting walls(d) Uniform thickness of casting wallsI got this question during an interview.My question is from Product Design for Sand Castings topic in chapter Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I
What should be the ratio of rib thickness to wall thickness in castings for proper avoiding of concentration of metal at joints?(a) 1 to 2(b) >2(c) >1(d) 0.6 to 0.8I have been asked this question in final exam.Query is from Product Design for Sand Castings topic in chapter Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I
In the solidification process, external angles have a lower cooling rate than re-entrant angles of the casting.(a) True(b) FalseThis question was posed to me during an interview.Enquiry is from Product Design for Sand Castings in section Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I
Why is inoculation done certain times during melting of cast iron?(a) To enhance its mechanical properties(b) To reduce the liquid shrinkage of metal(c) To enhance the surface finishing(d) All of the mentionedThis question was addressed to me in semester exam.My question is based upon Furnaces for Melting in section Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I
Which of the following gases can be beneficial in imparting certain desirable qualities to the castings?(a) Oxygen(b) Nitrogen(c) Hydrogen(d) Carbon monoxideI had been asked this question during an online exam.This intriguing question originated from Gases in Metals in section Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I
Breaking of the sand mould is done after sufficient cooling of castings, to have_____(a) proper surface finish of castings(b) no any distortion to castings(c) high casting yield(d) less casting yieldThis question was addressed to me in homework.My question is from Casting Cleaning topic in section Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I
Analysis of variations in the foundry procedures has no affect on the economy of production.(a) True(b) FalseI got this question in a national level competition.My query is from Product Design for Sand Castings topic in section Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I
Positive temperature gradient which gradually increases towards the feed head, avoid shrinkage defects.(a) True(b) FalseI got this question by my college professor while I was bunking the class.My doubt is from Product Design for Sand Castings topic in division Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I
Which of the following methods is best for preventing the solutions of gases in metals?(a) Bubbling of gas(b) Vacuum melting(c) Venting arrangement(d) Elements inclusionThe question was posed to me during an interview.This intriguing question originated from Gases in Metals in portion Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I
Non-uniform cross-sectional areas of the high temperature casting lead to having hot spots in the casting.(a) True(b) FalseThis question was posed to me by my college professor while I was bunking the class.My question is based upon Product Design for Sand Castings topic in division Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment