First off, there is nothing wrong with that body lens combo
I clicked though to flickr but no exif data showing, so it's hard to know what setting you were on for these shots - I'd advise you to leave the exif in place on shots that you are going to ask people to pass comment on as it can be helpful and aid feedback
Some thoughts on each image, all meant to be helpful, so please take it in the spirit it is intended:
1 - I think this would be better shot from the other side, so that you can read the logo/branding correctly. Other than that it is well exposed.
2 - Looks like a record shot, not all that inspiring or interesting if I am totally honest. The sky isn't adding much and if the digger parts are meant to be the subject then I think we need to be a lot closer in to get some of the details.
3 - Again, it's not really doing much for me in terms of subject interest. It also look to be slightly on the wonk, sloping from right to left to my eye
4 - Best of the bunch for me, lovely colours and well framed with a nice DoF. As a shot of some leaves it's great, but a wee birdy in there to focus the eye would only add to the shot imo
5 - Interesting composition, it's not central, yet not quite enough off centre to be comfortable to my eye at least. Good DoF though, separating your subject from the background nicely
6 - This is not sharp unfortunately - invisible exif means I can't be sure but I suspect too slow a shutter speed was used here. The sky is too bright and the shadows to dark. These things can be fixed in pp (how well depends on whether you shot in jpeg or raw). It looks to be leaning right to be too. Now, in terms of good points, I like the central composition and how you are using the rail lines to lead the viewer into the image, so you clearly have an eye for a shot.
I hope you don't take any of that personally, I am simply offering my opinion and hope that some of it might be helpful for next time. Keep shooting and keep posting your stuff up for feedback